Most countries will not permit that, except for the specific reason of adoption.
Let me answer this...
Since that poster changed the name later, definitely an Indian practice. So he belongs to India.
Now in India, We can change the name on birth certificate. There is a standard procedure:
1.Approach the nearest Notary office and explain the concern for change of name in Birth Certificate and make a affidavit.
2. Publish the name change in to reputed newspapers (One Local news paper where you are residing and One in a newspaper in the area permanent address)
Template for Newspaper Publication:
Here is the template for name change:
I,
Sri ___________________ (old name) have changed my name from __________________ (old name) to ______________ (new name) by affidavit sworn before the Notary Public, ______________ (place) on ___________ (date). Henceforth, I shall be known as _________________ (New Name) for all purposes. ______________ (Name) and _______________ (Complete postal address).
Signature
3. After publishing in news paper, submit the hard and scanned copies of the documents while applying the change of name in the certificate.
4. For publishing your name in the Official Gazette of your state, visit your local Government Press or the department that mobilizes Gazette notification.
5. Ask for two copies of Deed Changing Surname Form. Fill the form with all the correct details.
6. You can introduce yourself to a person of that department who can help you for Gazette Notification.
7. Which and Where to send your Documents:
> A letter to Secretary stating the name change.
> Deed Changing form
> News Paper Copies where the name change is published.
> A declaration given by you as given in the newspaper in the plain paper.
> Identity Proof (Photocopy)
As the child is a minor you and your wife have to make separate affidavits stating reasons for the name change in the Birth Certificate.
8. Submit all the documents to Secretary, Department of Commerce & Transport (Commerce) to your State's department.
In the template given above you need to make relevant changes as you would make it on behalf of your minor child.