Bro it will be difficult for you to get IIT by this score even in spot round counselling. But chances are there and you can also other options too.

And note that 644 is not a bad rank so chances are there. 

All the best for your future

Hope for the best. 

Hello Amit 

It will be tough as you know the EE paper was way easy seat bt IIT Madras and cutoff too went around 40. If it would have been last year then you could have got IIT BHU with this Score. 

See, if you really want IIT then you can wait for Winter Sesson as there you can easily get BHU.