Clarification on father's property division after his death

Dear Sir, Warm regards. I have some complicated situation regarding which I need your valuable suggestion. My father deceased in 1998 & he didn’t left any will regarding his property. As a property my father had only a house in Ahmedabad. At that time there were four legal members in our family: my mother, my elder brother, my elder sister & me. My brother & my sister were married at that time. After two years of my father’s death i.e. in year 2000 we had sold that house in Ahmedabad & transferred to Amritsar where we bought a new house. This new house was legally bought & registered in my mother’s name only. Since my mother was the head of family & she had no any source of any income or pension after my father’s death, no one has objection regarding this. After just six months, my brother also deceased in year 2000. Her wife along with her two daughters just left our house & started living with her parents in Delhi. She is still living with her parents & doing a job in Delhi from last