Property dispute among my deceased grandmother's daughters and my widow mother

A widow woman has a self acquired property having 2 daughters(married) and a son(died) leaving behind the widow and her son(myself the grandson of her) has made an agreement of room where my mother(widow of my grandmother's son) is a nominee and the room agreement was made in 2012.But in 2015 a quarrel broke out between my mother and my grandmother and due to this her both daughters took her along with the all the important documents with them and took care of her untill 2020 when my grandmother died at her young daughter's house. Now all the documents are with my deceased grandmother's daughters and they are playing with us a soft cat and mouse game. Now I am afraid that in the 5 years(2015-20) after the argument between my mother and my grandmother could she have made a separate will to exclude my mother and myself from the property right and include her daughters in it. I don't know anything about property rights.And I'm afraid that she would have made any changes or made a new will on her daughters name only excluding us. Please enlighten me.