Do not come here with too many expectations because you are most likely to get disappointed. My friend is currently in 3rd year of B.Tech at NIT Sikkim, and according to his first-hand experience, the hostel scenario is as follows:
BOYS HOSTEL
GIRLS HOSTEL
The hostels might not be the best in terms of infrastructure or facility, it all boils down to the memories you make during your journey. However, if hostel facilities are your topmost priority, then NIT Sikkim is not the place for you.