Change of name

In some cases, an " Affidavit" duly signed by the "Notary" is an acceptable document. In some cases, the competent authority of the concerned may require, an Affidavit, duly attested by a First Class Judicial Magistrate. It is depending upon the formalities of the concerned authorities. 

For change of name you can approach the Government Press for gazette notification and the formalities to be followed up in that regard.  The notary's signature if not accepted by some concerned authority, you cannot question their action,  it would be a part of their requirement which would be mandatory.

For name change it is better to approach the District Collector office.  The office people will explain you the procedure to follow.  (1) Notarised affidavit (2) Your Self Affidavit (3) Other forms ((4) Paper Publications in two noted papers (5) Gazette Notification (6) Again paper publication after gazette notification.  Whether signature of Judicial first class magistrate is cumplusory pl enquire. To my knowledge it is not necessary according to this procedure. 

Annexure E and 2 News Paper Cutting Would Solve Problem In case of Name change in Passport

I  D card of New Name is required