Ancestral Property and Gifted Property

Hi , This is with regards to Ancestral Property and a Property gifted . Recently my grandfather expired and he is survived by an aged bed ridden wife , 2 daughters and a son . He possessed some ancestral property which the son has got it transferred onto his name without the knowledge of the sisters and also got another piece of land which was on my grandmothers name transferred onto his name as a gift by forcing her to do so . Also it came to our recent knowledge that he has made himself as a nominee for all my grandfather's bank accounts . Now after the passing away of my grandfather, he has begun to show his true colors and is not contributing a penny for my grandmother s survival . She is now being taken care of by the daughters . Can we take any legal action against him to get the property to be fairly divided among my grandmother , the daughters and the son instead of the son having it all . Also what would be the chances of legally being able to get this fairly divided , would it take a long time to fight the legal battle and we get a resolution since my grandmother is aged and bed ridden she would be requiring financial assistance for her medical expenses .