I want to download NIOS 12th mark sheet from the digilocker app. But there is one problem, the registered mobile no.which is given in adhaar card has been changed.So,how can I link new mobile no.with the adhaar card ? How can I get my mark sheet through the digilocker app in mobile no.?

We are extremely sorry for the inconvenience caused to you. 
Please update your mobile number after entering your Aadhaar number and PIN while you sign into your account.
You will receive an OTP on your registered mobile number. Submit the OTP and you will be able to change your mobile number into your account.
In case of any issue, please write to us with screenshot of error. 
We also request you to provide us your current mobile number and Aadhaar number so that we can resolve the issue from backend.