Residential House Property Documents

Hi All, I am NRI and recently entered into a contract to sell my residential house, which is in Punjab. The buyer is constantly putting pressure on me to email him the copy of land title registry documents before making payment to me. But my friend who is in bank told me it is risky to email them the photocopy of original registry papers. But the property dealer and the buyer is putting pressure on me, They just gave my Maternal Uncle 5% deposit on my behalf only. The property is Prime and expensive. Please suggest. thanks