For the single owned property from oci is self owned and not taxable by way of rent but more then one one house if owned is taxable by way of rent.
Long term capital gains are taxed at 20% and short term gains shall be taxed at the applicable income tax slab rates for the NRI based on the total income which is taxable in India for the NRI.
TDS Deductible
When an NRI sells property, the buyer is liable to deduct TDS @ 20%. In case the property has been sold before 2 years(reduced from the date of purchase) a TDS of 30% shall be applicable.