Hello,

Sorry to say dear but 21 percentile is very poor. Your rank probably between 7lakh to 6 lakh. But in PWD rank may be less than that. I'll suggest you don't disappoint. You have to chance to give more 3 examination of JEE Mains. You will give those examination. And try to be improve your marks also. If you get 40 percentile next examination and then 50 or 60 percentile and lastly if you get 65 ot 70 percentile you will get definitely a good college. I know it's not easy but you can try. You will be successful in your career dear. I'll provide you a link below you can check it for know which college you will get in this rank.

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

All the best.