Hello

Greetings

Congratulations!!! Right Now Your rank is 20990

but Your Rank may change Either Your Percentile Score is Increases in the next attempt or Number of Student increases in the Next attempt the Number of Student Increases to 1400000 and Your percentile remain same then Your New rank would be 33605

Your rank is Good and There are chances that You will get NIT or GOOD government college but CS in Top NIT is not Possible.

If Your Percentile Score Increases in the Next attempt Then Your Rank would Be calculated By the Following Formula

 (100 - your total percentile score (Higher of two)) X Student appeared in JEE Main/100

You can Use the college Predictor to know about the possible colleges in which You may get admission by Just following the link given below

https://engineering.careers360.com/jee-main-college-predictor

Hope this Helps All the Best