How do I retain my home

My father built a 2 storey house in the year 1971.It is in mothers name. He expired in the year 1990.I am staying on first floor after I got married in Nov.1988. Presently I have two sons. My brother and mother were staying on ground floor but my brother went abroad (Dubai) in 1997 and from their he shifted to USA. Since 1997 my mother was staying alone on ground floor and I was on first floor.No issue ever came up regarding the house.I also have two sisters who got married in 1975 and 1977 respectively. In Nov. 2015 my mother has a stroke and my sister's son took her to Delhi at my sisters home without informing me.(She frequently visited my sister so I never paid much attention ).However later i was informed about her stroke and her operation in Max Hospital N.Delhi.Since then she has not returned back and insted sent me a notice to vacate the house as she wants to sell it. Kindly note that my mother has this habit of taking money from all and she even has some serious cases against her.My father knew about it and so he made a non registered family settelment dualy signed by me,my brother, father and mother.Although my brother used to send money to my mother but it was me taking care of my mother, electricity, housetax and even maintainance of house. Presently me and my family are staying on first florr and ground floor is locked. Can I stop my mother to sell the house as only I and my family suffers.