legal right

sir, My wife paternal grandfather died without will property in Chennai Perambur city limit he has three sons and four daughters wife died my wife is eldest daughter of eldest son of my grand father. kindly clear wife property legal right with following query 1.my wife only brother get settlement by cunningly got my wife and along with three sisters got it gift type settlement and not given single paisa to my sisters and three sisters, 2. during settlement he also got grandmother (wife of my grandfather ) her full shares by gift settlement 7 years before she is alive that time above registration done by my wife only brother. now the property in dispute not yet partition still my property in my wife grand father name he died 1964,and wife father died 2000 and mother is alive living with my brother kindly clarify me what is legal status of my wife her sisters, he not allowed to enter house anybody what steps is to be taken further.