My brother was in a similar dilemma when he had to choose between IIT Guwahati and IIT Roorkee for MTech in CSE. Eventually, he went for IIT Roorkee because his sole focus was to secure a job as soon as possible.
IIT Guwahati has better research opportunities and culture than IIT Roorkee.
All in all, if it’s a job you are after, IIT Roorkee is the best choice but if you want to pursue a career in research, IIT Guwahati is the best place for you.