The name change affidavit draws its authority from several statutes working together rather than from a single "name change law", which does not exist in India. The right to bear and change one's name has been read by the courts into the personal liberty guaranteed by Article 21 of the Constitution and the freedom of expression under Article 19(1)(a), so the act itself is lawful and needs no court permission for an adult of sound mind acting for honest reasons.
The affidavit's evidentiary backbone comes from the Oaths Act, 1969. Section 3 of that Act empowers courts, magistrates and notaries to administer the oath or affirmation, and an affidavit sworn before an unauthorised person is void. The Government of India's own consolidated text of the Oaths Act, 1969 on the official India Code portal sets out exactly who may administer these oaths and the forms of words used, and is the authoritative statutory source for affidavit oaths in India. Procedurally, Section 139 and Order XIX of the Code of Civil Procedure, 1908 govern how affidavits are verified and when they may stand as evidence. The notary's competence to attest flows from the Notaries Act, 1952, which gives a properly registered notary nationwide reach. Once attested, the document gains a presumption of regularity under Section 85 of the Indian Evidence Act, 1872, now carried forward into the Bharatiya Sakshya Adhiniyam, 2023.
The flip side of that solemnity is criminal exposure. A false statement in an affidavit is perjury, punishable under Section 227 of the Bharatiya Nyaya Sanhita, 2023 (the provision that replaced Section 193 of the old Penal Code). Everything you swear must be true to your own knowledge, because the oath converts a careless sentence into a prosecutable offence. The gazette stage is administered by the Department of Publication under the Directorate of Printing, and updating downstream records relies on instruments such as a general or specific power of attorney for banking and representation when you cannot appear in person.