In case of minor child whose both parents are citizens of India or one of the parents is a citizen of India, the following documents required for an OCI Card.
Copy of child”s birth certificate
Copy of Indian passport of the parents / one of the parents or copy of the Domicile Certificate or Nativity Certificate issued by the Competent Authority in respect of the parents/ one of the parents or any other proof substantiating the status of the parents/ one of the parents as being Indian citizen(s).
If the parents are divorced, the court order of dissolution of marriage, which specifically mentions that the legal custody of the child is with the parent who is applying for the OCI card.