You may have to be an Indian citizen to change your name in India.
If you hold a foreign country passport perhaps you may not be eligible for change of name as per law in India.
However the procedures for name change in India is that you have to first prepare an affidavit giving old and new name and reasons, if any, for desiring to change the name.
You have to furnish bath the old and new names in the affidavit which is to be duly notarised.
Subsequently the notarised affidavit has to be published in a local newspaper as well as government gazette publication.
The copy of the government gazette publication shall be the authentic proof for the changed name.