Lost Certificates

very first thing that u made a police complaing about missing of your certificate then after go to your previous school and made an affidavit for duplicate certificate copy, for passport police complaint is a good evidence in your hand.

go to your board and apply for certified/duplicate copies.

Apply to the board for duplicate

you need to fill up some forms necessary to obtain duplicate certificates from your respective board. There will be some fees regarding that and you may also have to get your declaration notarized with proper fee. Lastly, i would advise you to keep your documents, as important as Class 10 ,12 certificates, safely.