Degree in Physics from IIT (Kanpur) and training students for IIT JEE, KVPY, Math Olympiads
This is not yet announced formally. The rational behind aptitude test is to ensure that coaching will/ may not help in cracking an aptitude test. But, there is coaching for CAT entrance also. Until we know the format of the test and level of questions, it is difficult to say in my opinion. You can devote some time to do questions from various aptitude tests, may be SAT kind of test.
3rd year undergraduate at IIT Madras, IIT JEE Physics Tutor
The reason behind the Aptitude test, I think, is to check whether the student is really interested in Science and Engineering. If you already are and are not forced to do so, you needn't prepare at all. Those who are passionate, will effortlessly ace the test.