1. Mere payment of Rent & obtaining Receipt does NOT confer Title-Ownership rights on any property. At the most it will be construed that person is in possession or is a occupant.
2. Title Ownership documents (allotment letter or Sale Deed or Court order) is the sole criteria to determine absolute title-ownership of property.
3. Check the documents to find out the name of the allotment letter of the Central Govt. Land and also who documentary financed the construction of the house. This will determine as to who is the actual owner of house, for claim purposes.