Hello dear!
Congratulation to your son for obtaining such a good rank in jee main. Since his OBC-ncl category rank is 6999. He will not get computer science and engineering in any top IIITs but he may get a seat for electronic and communication engineering in his home state NIT.
For more information please comment in comment section.
Good luck....

Hey there,

Your son can get CSE at average nits like NIT JSR, IIIT Kalyani, IIIT Allahabad, NIT Agartala, Mizoram etc. I will suggest you to tell your son to join the NIT with this much score in jee mains. He can easily get the CSE branch at this much score.

I hope you have got the answer.

Good luck !