I'm doing a one month prep and I've just finished the Veritas intensive course in Mumbai, India. Don't really think it was very useful. Their material, although useful, is far from sufficient by itself. You'd definitely have to use other stuff to prepare.
Couple of good things though - They took individual lessons for all Quant topics, and that helps in strengthening your fundamentals.
Also, what i really liked was that they had plenty of practice problems per lesson to implement what you learn.
All in all, Veritas was decent, but not great.
Can't say anything about Kaplan or
PR.