I presume the question is regarding sale of real estate .
But I suspect that any property is actually sold in foreign currency in India at present. Anyway, if that is there then if the property is short term , normal tax rate applicable to Indian resident shall be applicable .In case it is long term asset, there is clear cut and separate rate given u/s 112 of the I T Ac. which is as under:
“112(1)(c) in the case of a non-resident (not being a company) or a foreign company,
(i) the amount of income-tax payable on the total income as reduced by the amount of such long-term capital gains, had the total income as so reduced been its total income ; and
(ii) the amount of income-tax calculated on such long-term capital gains at the rate of twenty per cent ;”
In effect waht it means is that the tax rate on long term capital gains is 20%.
However, important point to note that in case the the seller of the property is non resident at the time of sale , the buyer may have to deduct the tax at source u/s 195 of the I T Act which is at much higher rate than normal long term capital gains tax rate @ 20%.You would better read this posting to know how you can save your self from such deduction.