Welfare of child is paramount consideration 

2) your sister can come to delhi with children file DV case against husband seek alternative accommodation, maintenance and compensation for mental torture undergone by her , custody of her children 

Hello, 

Since all the children have crossed the age of 6 the matter of custody will be decided by the court. 

Welfare of the child is of prime importance while deciding the same. 

if she is just signing the document then in that case she can be denied the maintenance. 

Ask her to stop signing the cheque and stop submitting to the husband. 

Regards  

Dear Sir,

There are several enactments in favor of married women.  Your sister must show heat of the litigation to her husband otherwise your sister cannot sustain in such unbearable atmosphere.  Your sister can file Domestic Violence case.

Take power of attorney from your sister and file Domestic Violence case seeking following reliefs:

PRAYER

                HENCE THE APPLICANT HUMBLY PRAYS

1. to take cognizance for the offence punishable u/s 498A IPC and punish Respondent1 to 3 as per law and extend police protection to the deponent,
2. Pass orders u/s 19, based upon S.17, granting separate residence for herself and her three children at a monthly rent of Rs. 20,000/- and advance of Rs. 5,00,000/-.
3. Pass orders u/s 18, in totality against Respondent1 to 3,
4. Pass orders u/s 20(i) granting Rs.25,000/- per month as maintenance for applicant and maintenance at the rate of Rs. 5,000/- each per month to her three children.
5. Pass orders granting Rs. 5,00,000/- for setting up house hold requirements, in granted residence, to make it livable, as the applicant cannot return to the house of Respondent1 as he is residing in the house of respondent No. 3, which is legally prohibited,
6. Pass orders granting litigation expenses of Rs.1,00,000/- as the applicant made to wander from pillar to post for getting legal aid to attend the Hon’ble Court, whereas, the Respondent1 falsely filed Divorce Petition.
7. The applicant also filed interim application supported by affidavit u/s 23(1) and (2) of D.V.Act,
8. That any other order/s, this Hon’ble Court deems fit, to meet the ends of justice, be passed.

Custody of child rest with mother only, better some how manage to bring her at your house than file FIR of  domestic violence and also mention the facts that wife is house wife and husband may have forged many documents after taking signatures on blank papers forcefully.

Simultaneously file application to claim maintiancne, court will grant interim maintenance within a month. She will get maintenance for her and children both.

Also mention cheques and blank papers in FIR and petition file in court.

Two options. Separation or divorce 

File suit for any of the above on ground of cruelty and claim custody of children. 

Engage one lawyer to deal the case. 

See firstly in this case file an FIR against the brother in law for harassment and mental.cruelty under Domestic violence act.

Secondly find out in what companies your sister is director see can legally seek share.from those companies if she has not received remuneration in past now she can get same.

Further kids are of mature age court can grant the custody as per there wish.

And also sister can claim maintenance for kids from father and for herself.

First of all u should be clear about the divorce process. Ur sister's husband is just threatening her but neither him or Ur sister has filed any petition of divorce. There r certain conditions for asking divorce from the spouse which is absent for Ur brother in law. He has no reason to divorce Ur sister.     2. As per the custody of children it arises only after divorce of husband & wife. Also d children r not so young. They r in their teens so court will first consider their will.                3. Thirdly as mentioned by u your sister is a house wife & she is just a dummy director in her husband business for tax adjustment purpose. She doesn't own any profile in his business. So she will b considered as doing benami transaction for business purposes. Therefore nothing i.e cash or property etc belongs to her.                                                    4. In this case if u want maintenance for Ur sister she can claim for both herself & her children by filing a case of maintenance under sec 125 CrPC.                                          5. Since she has a troublesome husband and father in law she can file a case of Domestic violence where she can claim all rights for her including maintenance, protection residential etc.                                                     6. It seems u people r not much aware of the married women rights. Please do not panic. Instead approach a good lawyer in your area to help u out. Ur brother in law is just trying to scare u away by dominating. U should take strong steps against him. Ask your sister to stop being meek & docile and fight back.

- If, your parents are living in Delhi, then she can file her case from Delhi as well, otherwise she is having her right to file a case from any part of India.

- Firstly, she should file a complaint with Women cell (CWC) in Delhi , against those all persons, who are making her life a hell. 

- If, the matter will not amicably settled , then they will lodge an FIR againts them . 

- Further she can file a petition under the domestice voilence Act , and maintenance case as well.

- Mere showing as a partner of the company is not enough for denying maintenance , her husband will have to proof that she is getting salary from the same , and your sister can deny the same. 

- Custody of childrens will be decided by the court. 

- Lawyers are bound to follow the law, and not the clients , her husband can not get relief on the ground of expensive lawyer. 

- You can approach me in Delhi for pursuing the case. 

From examining all the facts of your query I want to say that-

These cases are very common in various courts of India and Supreme Court of India. I can understand your family's problem in this regard. There are some incidents that happen in your life and those incidents are so strong that they change your DNA. At times, despite our best efforts, life takes a turn for the worst. We may have wanted different things from life, but life’s got its own plan as well. A bad marriage is something which nobody hopes for, but at times, that’s exactly what we are given and forced to face head on.Marriages are hard. Divorces…even harder. Nobody enters marriage thinking about a divorce in the end. If some are unable to cope with the harsh realities of marriage, the only viable option in front of them is to approach the Court and seek legal separation. You know marriage doesn't guarantee that you will be together forever, it's only paper. It takes trust, respect, friendship, faith and understanding to make it last. Moreover, relationship without trust is like a car without gas you can stay in it as long as you want but it won't go anywhere. 

Your sister has many options available now. I feel that now your sister's relationship is deteriorated to a very high extent. Now, your sister has two options available either to file a divorce petition of mutual divorce or contested divorce petition on the grounds of cruelty. Divorce by Mutual Consent or Mutual Divorce is when both husband and wife mutually agree that they cannot live together anymore and that the best solution being Divorce, they would present a Mutual Divorce petition jointly before the honourable court, without putting forth any allegations against each other. Your sister can decide about child custody with your brother in law mutually. If her husband doesn’t agree for mutual divorce then she can file for divorce on the ground of cruelty.

In Supreme Court case of V. Bhagat v. D. Bhagat (Mrs.) it was held that mental cruelty in Section 13(1)(i-a) can broadly be defined as that conduct which inflicts upon the other party such mental pain and suffering as would make it not possible for that party to live with the other. In other words, mental cruelty must be of such a nature that the parties cannot reasonably be expected to live together. The situation must be such that the wronged party cannot reasonably be asked to put up with such conduct and continue to live with the other party. It is not necessary to prove that the mental cruelty is such as to cause injury to the health of the petitioner. While arriving at such conclusion, regard must be had to the social status, educational level of the parties, the society they move in, the possibility or otherwise of the parties ever living together in case they are already living apart and all other relevant facts and circumstances which it is neither possible nor desirable to set out exhaustively. What is cruelty in one case may not amount to cruelty in another case. It is a matter to be Determined in each case having regard to the facts and circumstances of that case. If it is a case of accusations and allegations, regard must also be had to the context in which they were made.

I have observed that over the years, there is a shift from custody and access being the 'right of a parent' to being the 'right of a child'. The non-negotiable principle on which custody is decided is the 'best interest and welfare of the child'. Who will best serve the child's emotional, educational, social and medical needs are the only criteria. The earning capacity of the parent does not determine custody but the capacity to provide a safe and secure environment does. A non-earning mother will not be disqualified but the earning father will be asked to provide child support. While the mother is the preferred custodial parent when the child is of a tender age, once the child attains a discernible age, his/her wishes will be considered while deciding the issue of custody and access. She can claim child custody by filing an appropriate petition in the court of law.

You may contact my secretary to connect with me for clarification.

Gopal Verma,

Advocate-on-Record & Amicus Curiae,

Supreme Court of India

Your sister can decide about leaving her matrimonial home due to the intolerable tortures and cruelties he has meted out to her.

She can claim maintenance from him for her and for the children.

She should leave the house along with her children, she can take shelter in her parents house also till such time a consensus is arrived between the couple.

Besides maintenance claim, she can file DV case seeking protection, residence, maintenance, compensation for his violent activities and tortures.

She can contact a CA and seek for getting her share of profit from his company as its director 

First let she take shelter in her parents house and operate  from there by filing all such cases.

She needs to file domestic violence case and seek maintenance and custody of children. She needs to also pursue  125 crpc for Maintenance

you sister can file Dv and 125 CRPC against your brother in law. for custody of child , You can file petition for custody before the family court. 

If she want custody of children then she should come to your house along with children and file case of domestic violence against her husband and father in law. 

In that case she should pray for protection maintenance compensation and custody of her children.

If he claim that she is director in some companies then she should claim her rights from those companies for her income and maintenance.