Hey,
Well,yes you can take admission in IIT in 2020 after qualifying JEE Mains and JEE Advanced 2020.
The eligibility criteria in terms of the educational qualifications requires you to complete your 12th from any recognised board or you be in top twenty percentile in 12th examination conducted by your respective board.
Follow the link given below for detailed information about JEE:
https://engineering.careers360.com/articles/jee-main-eligibility-criteria/amp#aoh=15616545962344&amp_ct=1561654601093&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s
Hope this helps.
Good luck.

Hello aspirant!
You can surely qualify if you touch their benchmark marks. If you're confident that you can score the marks after taking the drop then you can consider taking it or else try once again.
Hope this helps