Procedure for share in grandfather's property registered with brother.

Good morning. I am GPCR, from karimnagar , Telangana. My mother(Hindu) who got married in 1982 survived with 3 elder sisters and one elder brother. She is the youngest. Her father (my grand father) died in 2001 and grand mother died in 2014. All the property after the death of my grand father was taken by his only son. Still few of the lands are on the name of my grand father only. Now , can my mother claim the share in the property? According to 2005 November ruling of SC, i understood that she don't have the right. But what is NTR law in AP? What it says? Is she eligible according to that?my grand father didn't earn anything on his own. It's purely ancestral property. If we challenge in court, will there be any benefit for us? All the four sisters together have to file a case or alone also can? Kindly clear all my doubts. Thank you.