Hello,

I am sorry to heat that but don't worry. Just simply follow the procedure i am mentioning below.

Firstly file an FIR in the nearest Police station.

Fill an application form by downloading it from cbse website in pdf foramt.

Fill the application form carefully.

Make an Affidavit on Non-Judicial Stamp Paper of Rs.10 and prepare a Demand draft for the requisite amount.

Attach identification certificate of a gazetted officer or principal.

Attach the new paper declaration/press release.

Send to CBSE regional office with all attachments.

I hope this helps.

Hii!
If you have recently lost it, you can apply for a duplicate marksheet on the official website of the respective board of education you completed class 10th with, after filling an FIR at the nearest police station. You will have to go through the process first and then, submit an application for the same so as to get a duplicate marksheet of class 10th. You need to check out your roll no. And other valid details too.
Hope this helps.
Good luck!