Permanent legal guardianship of child

My daughter was born via surrogacy. I am a naturalized American citizen with Overseas Citizen of India status, and my daughter is also therefore an American citizen and an OCI. My partner is an American citizen by birth, and we are in India frequently for months at a time for work or visiting family. What legal documents are required to grant permanent legal guardianship in India of my daughter to my partner so that he can take decisions about her health care, money matters etc. in my absence, and act like her parent in these matters?