1) continue with your divorce case 

2) seek sole custody of your child 

3) mention wife not sending child to school for 6months , suffers from mental illness not taking care of child 

4) welfare of child is paramount consideration 

5) court should award you sole custody of your child 

See at this stage it would be better if you personally go and check on them both and further take help of Child and women Commission as from court order also it will take time and you cannot force her on order execution of same has to be filed. 

Continue with litigation

you can also file early hearing application in the ongoing child custody case with prayer to provide you immediate relief in shape of granting interim custody for Welfare of child mentioning facts (not going to school, wife mental status)

you can also make an application to the child welfare commission to get a Quick relief because Court proceedings take TIME 

you are also advised to settle the matter amicably with your wife as she might be facing mental trauma due to cases and mental sickness

Dear Sir,

It is very heartening to note that some parents spoil the matrimonial life of their daughters by unnecessary interference and you are one of such victims. It is also important to note you have still soft corner for your wife. Since, the legal process takes time, you are suggested to take the case for mediation and give a try to solve the things. In worst case, you should get rid of all the trauma by divorce and child custody, but if you take this step, you will have all the mental satisfaction of trying everything possible. Get the child visitation rights for this summer break through Court and be with child on order to take care and convince for better future through your steps.

It used to be the case few years before, but a recent ruling by the supreme court has put such things on seeking divorce due to Schizophrenia not a viable option any more. 

Mental illness is not a disqualification if it is treated and the parent can safely care for the child.

If your wife tries to get physically sole custody, you should have a lawyer to make the best possible case on your behalf.

1) Try to get one meeting all of you with family counselor, all means (you, wife, child and your in laws).

2) This is not matter of physically divorce as this consent with mental condition of your wife and due to this your  child's life and future is getting spoiled.

3) You have to sort this problem by way of talk and not by legal fight, because in most of the cases court grants child custody to mother. here in your case first you need to prove that she is suffering from schizophrenia. So try to sort this issue outside the court if you want child custody.

1) You need to attend each and every hearing in the court ask you lawyer to get the case stand as fast as possible because 5 years has been past to take decision on one case. Try to get ex parte decision.

if you pick the child and your wife commits suicide you would be charged with abetment to suicide 

You have already filed for child custody . Wait for court orders on your application 

Dear Sir,

As an option, you may file an application under section 97 Cr PC to the SSP/SP of your district to trace the child. You may also obtain an absent certificate from school and file the urgent application in the court for custody of child. Talk and discuss with your advocate in this regard.   

See you can file a petition in high court citing critical situation high court can pass orders. See in case something goes wrong there will be problems.

On the said medical condition you can claim for interim custody of your child as well as divorce from wife

Rightly advise by lawyer . Pick child and inform police. 

1. Please don’t follow what your lawyer has suggested you as she may file a criminal complaint against you for kidnaping though it is very hard to prove that father has kidnapped his own child, but yes without the consent of the guardian (mother at this point) you may be in trouble.
2. You should file Writ petition before the Hon’ble High Court in the nature of Mandamus under article 226 of our Constitution seeking expedite hearing of the custody application as delay may cause some danger to the child.
3. Once the order passed, move an application for early hearing in the lower court and get the matter decided as soon as possible.
4. There can be one more speedy way, but may need immediate action.

you can approach Hih Court for speedy action,

and,

Yes,

your lawyer is right, take the child and inform the police, but, the child may be sent to some NGO/Centre, etc till police get any appropriate orders in this regard

You file a petition before court seeking interim custody of the child owing to the reasons that the child's health and its studies as well as the future is under stake due to her negligent attitude and also her ailment.

If your lawyer is not cooperative you may change the lawyer immediately.

You may concentrate on the divorce case also properly.

If you feel that the court cases will not solve your immediate problem and if you are really interested in your child's welfare, you may adopt the steps as suggested by your lawyer  by taking away the child from her custody and also as advised you may inform the police about this so that if she commits suicide or anything you can be safe at Pune since a complaint has already been given to this effect earlier.