Hi aspirant,

One can fill the application form for CUET even without class 12th marksheet or entering his or her marks this is because there are many appearing candidates who are going to attempt CUET. Actually for filling the form one would need to upload the photo of your photograph, signature and Class 10th documents in the specified format and size in the section of documents upload. For class 12 you would only need to enter the details about the school, location etc but  you need not upload the marksheet.

To know more about the same visit the link given below

https://university.careers360.com/articles/cucet-application-form

Hope it helps!