My property is in possession of my cousin and he construct alter

I live in a house which had been sold by the owner in two sell deed.. Firstly on my grandmother's name .. Half of the south portion which consist two rooms and a latterin and bathroom.and a choch facing toward west main gate direction In 26 DEC 1974. Later on he sold the northen half part to my mother on 27july 1975 .which consist two rooms two kitchen and a chock toward north east direction and a varanda . From the beginning my chacha lives in all on my grandmothers property includes one of our kitchen. Now when I came to know I ask him to leave but he denied he is reconstruct the kitchen and in mid of it.. Now if I take a stay..on his construction.. Does the court will hold.. Secondly. In my grandmother's sale deed.. The word used half of the property.. And then written which consist two room and a latterin and bathroom.. But there south side also have a stairs and a passage to go outside...and a varanda which only written in my mothers sell deed.. Now what it legally meant..plz clear the issue.. There is no map and measurement given in both the sell deed..