I purchased a plot in Hyderabad a worth of 20 lakh rupees. 3 lakh 60 thousand rupees was paid by check and remaining amount paid in cash as the layout owner insisted me to pay only by cash. Registration yet be done. Now the layout owner saying that, after the registration of the plot I have to return sale agreement and all the payment receipts then only he will hand over the registered sale deed document to me. But I'll not have any proof of payment for the remaining amount of 16 lakh and 40 thousand if I return the payment receipts, which will be a problem for me incase of any future land disputes. Right now I have the receipts for full payment of 20 lakhs and sale agreement. Actually speaking I am not supposed to return the receipts but he is not agreeing for that. He is not even ready to cancel the agreement and payback the money too. Can I notarize payment receipts so that legally they will be valid as proof of payment for future use. or any other better way I can safe guard myself.