Hello,

I hope you are doing fine, Don't worry. Improvement exams are conducted to improve your academic marks so if your improvement exam result marks are less than your previous year marks then then you can use your previous year mark sheet but if you have scored more than your previous year marks and did nor appear in rest of the 2 exams then your marks of only that subject will be considered and the rest marks will be same as your previous year.

I hope you find this information helpful. I wish you all the best for your future.

Good Luck