Hi Shivam Sahu.

If your OBC category rank in JEE Adv is 6784, you won't be getting admission in any of the IITs. The cutoff for OBC category usually comes around 4000. With that, I don't think you have anything else to do with JEE Adv rank. You can tryu for NIT/IIIT with your JEE main rank.

Good Luck.

Kindly refer this link . It will give you an idea for last year's statistics of branch opening and closing of various IITs under each category.
If you have cleared the OBC cutoff you can get a seat as per your OBC rank.



Also, you can check the same site for NITs and IIITs opening and closing ranks there too. Various GFTIs statistics are also given.
Apart from that you can try for state colleges or private ones.
All the best!