1) As per the Indian Income Tax Act, when a resident purchases any property from a non resident, he has to deduct income tax (TDS) and pay the balance amount to the seller.
2)purchaser has to deduct 20% of the sale consideration as tax,
3) as per section 195 of IT Act, the person who is paying any sum to a non resident is responsible for deducting tax before making payment or crediting the payment in his account. So, the buyer of the property is responsible for deducting tax.
4)you or the seller can make an application to Income Tax Officer, working out the tax on capital gain and seek a certificate from him for lower deduction or Nil deduction of tax;
5) in case NRI seller is willing to re-invest capital gain to save capital gain tax: In this case, NRI Seller can apply for Tax Exemption Certificate.