Dear aspirant,

I'm glad that you want to improve your Class 12 scores by giving the optional improvement exam. Fortunately, yes, you can give the improvement exam regardless of your admission in a college/university. It it solely your choice if you want to give the exam but bear this in mind that the scores you get in the improvement exam will be the final scores so only give the exams if you think you are well prepared. I wish you the best of luck.

Hope this helps!

Good Luck!