Property Issue Between Grand Son, Grand Mother And Uncle

My grand-grand father buy land, he had five children, two sons three daughters. He died, then his land is divided into two sons and daughters also supported it. Thus my grandfather becomes the owner of the land. He has done two marriages in his life. one after another. My father is the son of his first wife. After some time my grandmother died of some disease. Then my grandfather married a new woman. He had four children from her. She is still alive. Now the thing is we live in same building with different floors. we live on the ground floor and other families live on the upper floors. My grandfather and father died. I live with my mother. there and I think the property is now on name of my grandmother. My father had electricity meter of his name in floor and water supply connection of his name. I regularly pay bills and connections are running from decades. We live here from birth. My question is: Can they throw us out of the house, do we have any kind of right on this property. if, then how to claim