Hello student, you can contact your Central board of secondary education regional office and ask them to help you in this situation or otherwise if you are a school student and you have filled the application with your school then your school must have your application number and the admit card.

All the Best!

Hey,

Application number is very important and is a necessity for downloading the CBSE compartment exam. As you have lost it, it is better to contact the CBSE officials or helpline number for helping you out. This is necessary because application number is only generated after submission and is not sent to any email id or phone number.