A deed of power of attorney is framed complying with laws of both the countries involved. The deed is tobe made sustainable to legal challenge by notarising it from the authorized officer in the Indian Consulate/Embassy as he is a valid notary under Indian law under section 3, Diplomatic and Consular Officers (Oaths and Fees) Act, 1948.
Once the deed is executed from the embassy, it is sent to India for registration along with all the signatures and the payment of stamp fees according to section 2(17) along with schedule I of Indian Stamp Act, 1899. Once registration is done under the adjudication of the sub-registrar, the legality of document can be proved in the court of law beyond all reasonable doubts.
Ministry of external affairs, Government of India has issued a notification L161/1/2003 In March 31st 2006 accepting the Hague convention and entering into force for India on 14th July 2006.