My grandmother constructed a house in 3 cents in naththam land and got a Patta for in 1978. From that time itself my parents and grandma were living there. After building collaps my parents made a a palm leaf tent and were living still there. My grandma passed away in the year 2000. Now some third persons came and ask us to vacate the place, and they saying they got patta for that land..is it possible?