Sorry Abhishek , what you are saying , I don't think it is possible. You are saying that you have 390695 rank in JEE mains. 

If I consider you as general category. And forget the category your rank is too much for all the categories. And still you want to pursue CSE. I don't think that you will get any government college. 

But you might try for some private colleges , there you might get admission. Or you can drop and study hard and prepare for next year and get above 99 Percentile to get CSE branch in NIT's. 

Hope it helps.

Thank you .