Inheritance

My father and his friend collectively bought a peice of land in 1976 from KDA in the name of my mother and his friend and subsequently got the plot registered in name of above two( mother and fathers friend).After retirement from the job , fathers friend left Kanpur in 1979 to got himself settled in his home town giving the right of the entire property to my mother in the form of Affidavit After he had left Kanpur we were not in contact with him there after. In 1980 my father constructed a house on the plot and we moved in the house in December 1980. My mother and father died in the year 2001 and father in 2003 respectively without writing the will .In the year 2015 when we approached the development Authority to register the property in our name they said you can claim your ownership on only half of its part as both your mother and father have died and your fathers friend is untraceable. Dispite living in the house since 1980 and paying all the expenses i.e electricity bill, water tax , house tax and having all the papers with us the Authority employee's are making us run from pilar to post. Now could we file a legal suit in the court of law for claiming legal ownership of the above property.