I am a buyer, whether I should deduct TDS on Property from the amount exceeding the property value of 50 Lakhs or on the whole amount of property sold?

Ans. For example, If amount of   property sold is ₹ 70 Lakhs, would TDS be calculated at '20 Lakhs or on '70 Lakhs?

TDS is to be deducted on the amount paid/credited to the seller. In the above e.g. the deduction will be on total amount i.e. on '70 Lakhs.