PIO can sell property in India to a person resident in India or an NRI. In case a PIO wants to sell to another PIO, he will need to get prior approval from RBI.PIO can transfer residential or commercial property in India by way of gift to a person resident in India or to a person resident outside India, who is a citizen of India or to a Person of Indian Origin resident outside India.A Non Resident is liable to pay tax on the gains out of sell of inherited properties. The purchase price for calculation of capital gains will be the purchase price paid by the person who bequeathed the property.Selling of immovable property by a Non Resident Indian is taxable under the income tax under Chapter XII-A of the Income Tax Act, more specifically under section 115E of the Income Tax Act 1961.Though inherited property will not be taxed in the hands of non-resident, but one needs to know any income from such property will be taxed if any gains generated out of sell (whether short term or long term gains). Even rental income is subject to applicable TDS.The sale proceeds may be credited to NRO account.
NRIs/PIO to repatriate the sale proceeds of the immovable property inherited from a person resident in India subject to the following conditions:
(i) The amount should not exceed USD one million, per financial year
(ii) This is subject to production of documentary evidence in support of acquisition / inheritance of assets and an undertaking by the remitter and certificate by a Chartered Accountant in the formats prescribed by the Central Board of Direct Taxes vide their Circular No.4/2009 dated June 29, 2009
(iii) In cases of deed of settlement made by either of his parents or a close relative (as defined in section 6 of the Companies Act, 1956) and the settlement taking effect on the death of the settler
(iv) the original deed of settlement and a tax clearance / No Objection Certificate from the Income-Tax Authority should be produced for the remittance
(v) Where the remittance as above is made in more than one installment, the remittance of all such installments shall be made through the same Authorised Dealer
(vi) In case of a foreign national, sale proceeds can be repatriated if the property is inherited from a person resident outside India with the prior approval of the Reserve Bank. The foreign national has to approach the Reserve Bank with documentary evidence in support of inheritance of the immovable property and the undertaking and the C.A. Certificate mentioned above.
Refer : https://www.rbi.org.in/Scripts/NotificationUser.aspx?Id=984&Mode=0#c-10
In your case you can act as a power of attorney for them but must comply with all the acts said above.