The shortage is most acute in IIT Roorkee, which has a sanctioned strength of 575 faculty, though only 345 faculty members are in position.
IIT Delhi faces a 28% shortage: of the sanctioned strength of 583, only 418 are in position. IIT Guwahati has the best figures and faces a shortage of only five faculty members.
From this report. This takes on an urgency because the government is mulling the possibility of increasing the intake this year by almost 50%, so as to 'protect' the number of general quota seats from being eroded by reservation.
At the IIMs, the faculty shortage is pegged at about 8%. The inability of IITs to attract quality faculty is something that I understand (I think ...); the salary, start-up grants, lab facilities, teaching load (particularly for junior faculty) are some of the deterrents, which make prospective candidates think of other places which treat them better on these parameters (except, of course, the salary, which is fixed by the government).
Since I am not familiar with the IIMs, I am not able to comment on the shortage there. However, I understand that consulting is encouraged in IIMs, and consulting and EDPs (Executive Development Programs) can be quite lucrative. A recent report in the Economic Times covered this aspect of being on the IIM faculty:
[...] Under the Fifth Pay Commission, the entry-level salary of an assistant professor at IIM-A is Rs 12,000 a month while the maximum salary of a professor is Rs 22,400 per month.
But one area where the faculty end up making Rs 23 lakh per annum alone is consulting with private or government firms. This includes consulting done under two slabs. First, the faculty can do consulting worth Rs 6 lakh which they do not have to share with the institute, and is called ‘free allowance’ . Once the Rs 6-lakh mark is reached, the faculty is allowed an additional 52 hours of consulting a year — at Rs 75,000 an hour — 50 per cent of which is shared with the institute.
BTW, isn't there an error (and possibly two) in the last sentence?