There is no law enacted by Parliament that before changing name of a City, permission of Central Govt is required.
And yet… Yes, since more than 66 years, State Governments continue to send such such name change proposals to Central Government for clearance. And the Central Govt keeps sitting on such proposals for years!
Strange! Ignorance of Law! Either on my side or on sides of State Law Makers of India!
Do you want to change name of Allahabad to Prayag, or From Ahmedabad to Karnavati?
Well, tell law makers of your state that there is no need to ask from clearance of name change from Central Government unless they saw you some valid law.