Dear Aspirant,

Yes you can apply for improvement exam, if you are not satisfied with your marks in boards, however, you  must have to appear for all the subjects in improvement if you are aiming for JEE advanced as it require the improvement to be filled in every subject.

Hope this helps. Thank you.

Hello dear student !

Improvement exams are basically for the students who have passed the examination but are not satisfied with their marks so they want to give the exam again. And the condition to fill the improvement form is that you can give the exam only if you have passed in that subject. So, yes of course you can apply for the improvement exam in cbse class 12th in the succeeding year. The examination would take place in the following year and student can't appear if he/she has failed the examination. The fees per subject to be submitted is INR 200 (Subject to change) .

Hope this will help you!