Dear Rajesh s/o V Srinivasan. You have ended up in mess. Rectify it as soon as. You go to public notary in your place. Get an affidavit made. Go along with all the proof of your fathers name/his school leaving certificate/his PAN number. Also take all your different certificates bearing different names. Take everything that bears different name. Everything. Ask the notary to make an affidavit. They are expert and they will make an affidavit saying mr x, mr y , mr z are the same person known as sososo.. From now on he will be called as so soso .. Also have to advertise in the local newspaper of the name change/name clarification. Keep a paper cutting/clip with you. With those proof, please apply to tax department for name change. Also for your knowledge -- surname = family name, first name is own name, initial = fathers name = middle name. Good luck. Vishal.