Hello Tanuj

Candidates applying for admission to IIITs, NITs and CFTIs after qualifying JEE Mains and JEE Advanced are advised to refer to eligibility criteria of JoSAA 2019. Candidates applying for admission must meet the qualification and requirements of listed under JoSAA 2019 eligibility criteria. 

Careers360 have done a proper evaluation regarding this in one of their article. I am giving you the link you can understand it in better way.

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

Good luck.