Hey,

To pursue B.Tech in computer science from IITs, you must qualify JEE mains exam. 
•JEE Advanced (Joint entrance examination) is the only entrance exam to get admission into B.Tech courses in IITs.

•B.des (Bachelor of design) is an undergraduate degree course in the field of design. To pursue B.des from IIT, you must have appeared in UCEED exam.

Hope it helps!