Since this error occurs   only in the 12th  and UG certificate  and if it has not caused any trouble of problem so far in this regard because you have already obtained passport, PAN card and aadhar card which are vital and have identical and correctly spelt name, you may ignore this minor error or if you still want to have it correct then you may have to prepare an affidavit staying that this was erroneously mentioned as so and so in the said certificates, however you are known by both the names.

Along with a public notice published in a local newspaper you can keep this affidavit with your certificates to prove it as evidence to the authorities concerned  for the correctional action taken by you in this regard. 

Execute affidavit that both are one and same person 

affidavit should be on Rs 100 stamp paper and duly notarised 

There no necessity of seeking gazette publication as you are not seeking change of name. You seek correction of name in 12th certificate. Draft an affidavit stating your correct and incorrect name mentioning all documentary proof of correct name. Notarize the affidavit and submit an application to Secondary Board for correction of spelling in the name with affidavit enclosing copies of all documents. Your name will be corrected in 12th certificate . For further clarification you may contact me through Pathlegal. Hit the like button if the advice is useful to you.   

Dear Ma'am/Sir, 

In order to get the name in your 12 std board mark sheet corrected you should personally visit the office of your board with the documents to support your claim such as you 10th grade mark sheet, addhar card, the certificate of leave granted by your school after 12 etc. All exam board have offices that deal specifically with such kind of matters. And in the interim if submission of your mark sheet is required somewhere you can file the same with an affidavit. Signed that the mark sheet belongs to you, if you are questioned on it. Though usually in practice 12 grade Marksheet are not required to be submitted anywhere except when applying for colleges. Usually when applying for any Govt ID only 10 grade Marksheet are asked for, because it contains birthdate of the student.

Thank you

- As per law, you cannot correct /change the names after 2 years from the date of passing that examination. 

- Since , you have already crossed this period of 2 years , then for correcting the same , court order needed .

- However, you can print a public notice after mentioning that your two different names are same and for one person only , and now you will known with Aarthi Kumar for all purposes.