To claim an ancestral property by legally

Hello Experts, I need an advice for my close Friend. He got married in 2007 and his wife expired in 2010. They are having one Kid and now the my friend and his relative are taking care of the Kid. My friend wife doesn’t have any property, insurance…etc on her name. But her father having some property, which basically her Grandfather/GrandMother ’s Property After 4 years is this possible to raise a case against his in-laws to claim Kid’s an ancestral property ( Kid's Mother Share) ? If yes, then 1. What are the docs needed to claim an ancestral property by Legally 2. Is this Legal Hire Certificate is mandatory to claim an ancestral property by Legally? Thanks in advance.