I don’t see why people keep comparing the older IIMs to newer ones. No matter how good a new IIM is doing, it can never compare to an older established IIM. The same is the case here. IIM Trichy and IIM Udaipur are indeed growing at an excellent rate, but IIM Shillong still is the winner of the race. This is because of its early establishment and being a member of the top IIMs family BLACKIS. That in itself is an accomplishment that the new IIMs have failed to achieve.
IIM Shillong is the 7th IIM and is among the top B Schools in India. Ever since its establishment, it has been growing at a tremendous pace and its placements are a testament to that. The brand value it enjoys because of being a part of BLACKIS is much more than any new IIM. This brand value helps you in the long run.