Wife property

Sir my friend had taken house on lease for 2 lakhs for three years from a person measuring 28x46 feet at 1998 after the expiry of the lease 3 years the person did not return the money but offered to sell the property for additional amount 350000 lakhs but at the time of agreement we came to know that it was his wife who had died intestate and the property was on her mother name and this person was house son in law so we demanded the money but he did not pay so we had gone to the advocate on the advise of the advocate we made the an agreement and we filed a sp suit and this person through a gpa holder appeared and a compromised memo and we had paid balance through court itself and filed in the month of october stating that he would register the same in a month but he did not do so hence we filed an ex petition in the month of november and the court had issued a notice and the matter was posted 15 dec and the gpa holder again filled the vakalath but the person has been dead on the 8 itself and fact is we did not know that and we gave a draft sale deed copy and the court registred it and we are paying taxes upto date meanwhile after that we got a notice that there relations are claiming right in the property and the case came to be dismissed after 12 years they have filled rfa and which is pending now my question is weather my is a successful owner or not