In India one of the best institute is TIME kolkata. I have taken classes of CAT exam in TIME. Very good classes are held by Time and also they provide required study material which is really helpful. High profile faculty take those classes on verbal and numerical ability.
Many short technique to solve numerical problem I have learned from TIME which is helpful for CAT as well as any competitive exam. They also provide demo test of CAT by which you can practice and get more confident. So if anyone wants to crack CAT please don’t think and take admission in TIME.