Grandmother property

Good evening sir iam from hyderabad Iam 3rd daughter 31yrs of my parents. We are 4 girls and one son. My father is only son of my grandparents. Since we are born my father left my mother and us as we all are girl children. She alone brought us with very great difficulties and my father did even looked after his parents too. He worked as a technical officer in ECIL with handsome salary but we dnt get any benefits from him. My query is we have some land of our grandmothers from anajipur village mothkur mandal Yadadri buvanaguri. My grandmother does not wants to give her property benefits to her son when she was alive on this issue my father beat his mother and took away her land passbooks. Does he have any rights on that property? . And do we have any rights on it? What we children can do on that property. Moreover my parents are divided my father gave divorce to my mother and married to another lady. Does she have any rights on my grandmother property. I have some videos of my grandmother saying she wants to give her property to his grandchildren. Does that videos with her presence valid further in any legal problems. Means does it works as an proof against my father. Please help me Sir. This is the only benefits which we can have since our birth.