Hello,

Both of them are renowned colleges of our country. You should decide upon which course you are more interested in. CSE surely has more scope in terms of job opportunities. ECE at NIT Raipur is also a safe option to choose as the placements are fine. Faculty and academics is great in both colleges. Infrastructure is better at IIIT Guwahati but it is comparatively a newer institution.

You may weigh factors like fees, course, location etc to take the final decision. 

All the best!