Property dispute

Dear legal experts, Please help me with this property issue by giving your valuable legal opinions. I stay in Bangalore. My father had purchased 3000sq.ft house about 40 year’s age. Since the house was narrow, house was made 2 partitions of 1500 sq ft each. In one portion my father lived and my father let his younger brother and his family to live in other portion. My father expired 3 years back and we 3 children (me and my 2 sisters) are legal heirs of this property. Hence we will be getting equal share in that property. Now the problem is, my father’s younger brother still lives in that portion, which was given to him 40 years back. Now we asked him to vacate that place . But they are refusing to do so saying that now that property belongs to him as he is living there from 40 years. Now even he tells that , he has also has invested in that property. When we asked him documents(agreement b/w him and my father) he said no agreement was made and there are no documents for what he said . But all legal documents ,titles , etc are my my fathers’ name. Actually due to his poor economic conditions my father let him to live there. It’s been 3 years we are asking them to vacate that place. But he is refusing by giving false statements and reasons. Even my mother passed away a year ago. Now I and my sisters have decided to sell that property and share amount among ourselves. But they are not giving us that property . Please help me in this regard. Please help me as how I can get my property back from their hands