To claim an ancestral property by legally

Dear Experts, It's an urgent need of your help and any timely inputs are highly appreciated. I need an advice for my close Friend, Who worked with me. 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/Mother ’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 Mothers Share )? If yes, then what is the Procedure and what are the docs needed to claim an ancestral property by Legally and Is this Legal Hire Certificate is mandatory to claim an ancestral property by Legally?