Need your advise: passport surname change

Change of surname is only optional but not mandatory for a woman.U can continue the same signatures U have been affixing before marriage.

Whether you want to change your surname or not is a personal choice. I'll advice you to get it changed in the Passport. You'll need a copy of your Marriage Certificate and an Affidavit stating that you wish to change your surname.

Now your husband's name is: Suresh (First Name) Kumar (Middle Name) Babu (Surname/Last Name). The middle name is always optional. I avoid it as it always leads to a confusion.

So your NEW name should be (if you keep your maiden surname): Amrita (First Name) Ghosh (Middle Name) Babu (Last Name)

OR

If you choose not to keep your maiden surname then: Amrita (First Name) Babu (Last Name)

Yes agree with Prashant and Sainath but Passport authority of India also validate one individual name change process also which is Gazatt declaration requester can use that one to change name as per wish