Firstly correct your question, it should be IIIT Delhi.

Well I acknowledge, you ahve three heavy quotas ie Delhi, Defence and then an OBC.

But somewhere I believe, still these quotas are not good enough to secure a seat at these colleges as you need to understand that your JEE mains rank is way too less.

But still I would recommend you to take part in JAC and to go to it's last round ie the spot round. I've personally observed, that upside-down do happens at JAC's spot round.

Thank You