If you want to change your surname after marriage then you can swear an Affidavit to that effect before the Executive Magistrate Cuttack.
You need an Affidavit which states that, from now onwards you shall be known as _________(your new name).
You can also produce this affidavit for change of your name in Adhaar or Voter Identity Cards and for other purposes.
For any legal assistance you can contact me
Mr. Amiya Ranjan
Mobile : 9238577260