In All documents of child like school leaving certificate, Pan Card, Aadhaar Card, Educational Certificate etc will be mother's name and nowhere mention as father's name. So she can hold all rights on child without having court's certificate of child's custody. 

There is no valid divorce. So your marital relationship exists under the eye of law. Either of you should not contract second marriage during the subsistence of the existing marriage.

1. If you are biological father of the child from a lawful marriage then your name must appear on the birth certificate  

2. Therefore write to the issuing authority about this anomaly and ask for inclusion of your name. 

3. Whether your name appears on the birth certificate or not of he is your own child he will inherit your ancestral property in all circumstances. 

You may not face any problem but your child to prove his paternity. Child surname always follows father surname till mother dose not get sole custody or single mother.

Wife will be in a position to carry her maiden  name with child and sole guardian of child 

You won’t face any problems 

she does not want you in child life in future 

she does not want to obtain your consent for child admission in school etc 

You will not have any issues. But if consent is not taken from you then you can object to the said name on BC

- Even you both living separate from each other , but the relation of husband & wife legally not break, and also for the son.

- Even she is having birth certificate from her own name , then legally you are the biological father of your son, and she cannot dis-entitle you from meeting with the son. 

- However you can ch allege the said birth certificate in the office of birth Registrar. 

-  She will hot get any benefit from the same , but you will be benefited from the same. 

Looks like M.Kumaran son of Mahalakshmi.

The child will grow without identity.

Nobody cares today for father's identity.

Hello,

1. As the biological father of the child, you have equal rights and liabilities for the child and as you are still husband and wife though separated, she could not have taken a unilateral decision to change the initial of the child.In future it cannot take away your position as the father of the child or deprive you of your rights and liabilities as father of the child.
2. Your wife does not have any personal benefit from the change in name, however, it can cause problems when she will have to seek admission for the child in school. You must seek access to the child and involve in its upbringing, so that you can influence decisions taken for the child.

Nor she can have any advantage neither you will face any disadvantage 

You are the biological father of your son. Your wife could not denied that status . If you want to make any changes in name  in birth certificate then it can be done by way of filing application before the office of birth registration. Settle the matters and differences between you and your wife at the earliest. Other wise it may make much head aches in future.  

You being the biological father of the child,  you can object to her changing the child's initials without your permission or consent. 

You can first issue a legal notice asking her to revert your child's name to the original one, if she's not responding then you can file a suit before family court seeking to direct her to do the needful. 

That doesn't matter. You are the father and will remain so. That is an act of revenge on her part.

Under the situation and facts of the case in the present post as narrated by you and rules of  law of Succession, your wife and children have full rights over your moveable, immovable ,self acquired and ancestral properties during and after your life.

Dear sir,

The initial will not affect any of your rights or obligations. You will not face any problems. Your wife will not get any benefit.

Best wishes. 

as a biological father your name must be appear in child birth certificate. 

you will not face any problem.. 

If doesnt matter if your child got birth certificate without your name or just with initial name of your son still if you want to add your name as father then you need to file a suit for mandatory injunction against your wife and registrar of birth and death.

Dear Sir/Madam,

No problem should occur in future except the complete custody of the child with her. 

1. As per the information mentioned in the present query, makes it clear that the separation of your wife and you is no separation in the eyes of law.
2. I would like to apprise you that you both are still spouses now also till the time you both are legally divorced.
3. It depend upon you to think as what exactly you want from child side as if you wish your name would be there you then you should approach her and if she says no then you have an option to approach the court of civil law for getting your need done as per your own wish and requirement.