Hello Aspirant,

Yes, it is compulsory for any student to avail caste category rank by their validity caste certificate. if you don't have validity caste certificate then the officials of counselling considering your common rank and not considering the caste catergory rank. if you want more information then go through this link.

https://www.google.com/amp/s/engineering.careers360.com/articles/josaa-counselling/amp

hope it helps you.

thank you.