Hello,

The cut off is different for each IIT.But to be able to get seat in Computer Science Engineering in IITs your rank must be in top 100 so that you have decent chances of getting seat in IITs like IIT-Bombay, IIT-Delhi, IIT-Kharagpur etc.Coming to second part of your question BE is more of theoretical and B.tech involves practical application.It isn't subject specific to classify CSE under BE or B.tech.There are colleges which offers B.E CSE and there are colleges which offers B.tech CSE.