Sale of property

My father bought a land measuring 4974 sqft in 1967.he executed a mortgage deed in favour of railways for a construction loan. He died in 1970.In 1973 with consent of all legal heirs the property was transfered to my mother by a Reconveyance deed by Railways. My mother was in possession of the property. In 1984 my mother made one settlement deed in my favour 1/2 Uds of 2810 sqft with right to construct I st floor. I took a loan from the bank and constructed. As per advice of my lawyer I took a notarised affidavit from my brothers and sisters as mother is the sole owner and she has all the rights. In 1991 my mother made one more settlement of 770 uds and ground floor house to me. My toal land area by settlement deed was 1405+770=2175 and building. In 2003 my mother along with legal heirs sold 2643 sq ft land to third party. Out of balance of 4974-2643=2331.which I was enjoying for the last 30 years. Now I want to sell my property in which I have document for 2175 sq ft and 156 sqft. I do not have dicument. How to create document since I was enjoying even 156 sqft land and sell. Kindly advise