I am the biological father of my daughter .my daughter mother has die. The grandmother has a custodial affadavid against me. I need to know what I have to do to get custudy of my daughter.

Welcome to AMHD. There's lots to this story you haven't explained. My best answer is to get a lawyer, and get things done legally and in good order. I've never heard the term, 'custodial affidavit'; sounds like a legal document the bio mother prepared to give the grandma something with which to maintain custody.