Hi,

If you already took admission, then there is no need to write PUC exam again. PUC Exams are for admission into the college, if you already get into the college with a desired degree, then there is no point of appearing again for the exam. If you want to improve score, you can appear for the exam. But, either, you need to rewrite the exams or take admission into the college. You cannot do these two things at the same time.