The procedures differ from state to state. The law does not differentiate between first name, middle name or surname. Any change, addition, deletion or modification in name or spellings amounts to name change irrespective of ground realities like marriage, divorce, change in religion or on numerological considerations. Kindly approach the concerned gazette office of your place to know the procedure which includes filling of forms, submission of desired affidavits, duly notorised, publishing in national and local newspapers, submission of fee for transfer of name in the authority’s office etc. The whole process may take 2-3 months to complete. Once the name change is gazetted, you can submit copy of gazette to the desired authority like PAN card etc requesting them for change in name. If they have any forms etc for this purpose that also needs to be filled. I hope this much information will suffice your purpose.