Property dispute

Hello, My Maternal grandmother has two daughters and two sons. My one uncle lives with her on the first floor and the other one with his family live on the ground floor, the one living on the ground floor and his wife and their daughter are mentally and emotionally harassing her for selling the property where they live, which is on the name of my maternal grand father's name who is no more. They have also threatened us to sell the property as soon as possible, but there is no other home for my Naani to live in, Daily there is some new kind of torture or fights or they will call us, earlier when my grandfather was alive, on a written agreement they agreed to leave the house for cash and they did so but after a year or so came back and started forcefully living at the same address. They have not even given a single penny to my grandmother after the demise of my grandfather. my uncle's son-in-law is related to some sort of politics and also has a very bad character and has even called and abused my mother and my naani, Now the things are out of control as they are demanding her to either give cash or leave the property. What are the possible options left with us for now?