You have give Power of authority sell her property in India, besides the following documents
An NRI, who want to sell a property in India, should hold a passport; not necessarily an Indian passport. This will serve as the identity proof of the person, involved in the transaction.
For an Overseas Citizen of India (OCI) and a Person of Indian Origin (PIO), a passport serves the same purpose.
A number of NRIs do not pay taxes in India, as their income is taxable in the countries they stay. However, experts believe NRIs should apply for a PAN (Permanent Account Number) card here when they intend to buy a property in India, as it will be required to apply for a tax exemption certificate as after the sale of the property. PAN numbers are given out to NRIs with a foreign communication address to select countries.
Also Read: An NRI Without A PAN? You Won't Have To Pay Higher Taxes Now
If an NRI has been holding a property for a certain period and earning money from it (by renting it out, etc), the transaction becomes taxable. In that case, tax returns for the whole property-ownership period should also be kept ready.
An NRI has to give documents in support of his address in India as well as abroad. This may include a ration card, telephone or electricity bills, life insurance policy statements, etc. Same set of papers are also required as the proof of residence abroad.