Surrender Indian Passport for child

I have a 4-year old child who has received his British Citizenship and now I want to apply for surrendering his Indian Passport.

Few queries:
1. Is the child required to come to surrender the passport? Can only one parent go to submit the application?
2. Signature box in the application - should I put my signature as the parent or a thumb print of the child?
3. One of the requirement was mentioned that self attested copy of each page of the passport, in case of a child, can this just be a copy or should be self attested by one of the parents?

1. Is the child required to come to surrender the passport?

Not required but, preferably take the child to the centre.

Can only one parent go to submit the application?

Yes BUT - make sure both parents have signed the application form consenting to the OCI. The parent not attending will have to attest their own passport copy. Otherwise get them to write up an No objection to the OCI.

2. Signature box in the application - should I put my signature as the parent or a thumb print of the child?

Rules say thumb print for children below 5.

3. One of the requirement was mentioned that self attested copy of each page of the passport, in case of a child, can this just be a copy or should be self attested by one of the parents?

The parent submitting the application must attest the documents except the passport copy of the second parent who needs to self attest theirs.