Hii!
Yes, if you want to improve your score and earn better percentage you should definitely apply for re -exam or improvement exam or repeat a year as a private candidate. What I suggest is don't entirely waste your year on it. Try getting admission into graduation or different courses and side by side apply and prepare for it. Remember, you need to be fully dedicated and focused this time. Be serious and study hard. Pay more attention to the subjects you are weak in and solve previous year question papers. This will help you earn good marks.
Hope this helps.
Good luck!