Which one is better: CS at Guwhati College or the IIT, Hyderabad?

It’s illogical to compare two programs as the choice of branches depends on individual preferences. I will share the limited knowledge I possess for IIT Hyderabad CSE.

• IIT Hyderabad CSE department is very dynamic and rigorous. 
• The CS department has excellent professors that are very learned and experienced.
• The student crowd comprised good quality students most of them being top rankers. There is tough competition between peers maintaining the dynamic academic environment.
• The average package for CSE in IIT Hyderabad is the highest of all the other branches, with many international offers too.
• As far as higher studies are concerned, if you plan to do an MS abroad, every year a lot of students get admitted to highly reputed foreign universities like Stanford, UIUC, Georgia tech, and ETH Zurich.

Since I have no information on IIT Guwahati, I recommend you contact a senior and discuss basic details.