If I buy any land/building then is there any requirement to deduct tax from the sale proceeds to be paid by me to the seller?
Yes, Finance Act, 2013 has introduced section 194-IA which provides for deduction of tax at source in case of payment of sale consideration of immovable property (other than rural agricultural land) to a resident. S​ection 194-IA is not applicable if the seller is a non-resident. Tax is to be deducted @ 1%. No tax is to be deducted if the consideration is below Rs. 50,00,0​00. If the sale consideration exceeds Rs. 50,00,000, then tax is to be deducted on the entire amount and not only on the amount exceeding Rs. 50,00,000.
If the seller is a non-resident then tax is be deducted under section 195 and not under section 194-IA. Thus, in case of purchase of property from non-resident TDS provisions of section 195​ will apply and not of section 194-IA