Hello student ,

As you have not mentioned your board from which you belong from but still mostly in cbse or isce if you have filled improvement and could not be able to give the exam then you will be not marked as absent , in your result card your previous exam marks will be alloted to you . So you don't need to worry if you will be not able to give the exam . But if you belong from another board then i will suggest you to consult with the faculty member of your school .

Hope it helps !