Why is the NIRF ranking of NIT Patna so low despite it being the oldest and best NIT?

The rankings released by bodies like NIRF are based on not one but several parameters like placements, academics, research, and campus life. So institutes are often ranked low when they fail to meet even one or two criteria.

NIT Patna has a very small campus around 40 acres, so that works against the institute's image and affects the rankings badly. The authorities had a tough time making its campus fully residential. However, the facilities are slowly being improved and new Mega Hostels have recently been constructed. 

Another reason for NIT Patna's diminished image is its location amidst the hustle and bustle of the city. While most NITs are located remotely away from the haptic city life, NIT Patna’s central location is another reason why NIT Patna has not been ranked decently.

But if you look at the big picture, many bright students have been able to get placed in huge companies like Adobe, Amazon, Qualcomm, NetApp, Infenera, etc As a whole, NIT Patna is at the same level as tier-II NITs at least in terms of placement and academics.