IIM

As per my experience I don't think that an year gap affects for CAT preparation adversely affects your chances of getting admission in any institute in IIMs or any other institute of India. The entire interview process is meant to gauge the students on their knowledge, skills and attitudes as well as their inclination of doing a MBA program.
If you are dropping out of your current job for one year there should be a justification as to what were the reason for opting out of your job. There are various examples of students who have scored a hundred percentile while working and thus the interviewers always discuss the reasons for dropping out. But, if you are able to justify it well and convince them about yourself. I personally don't think that it would negatively affect your chances into IIMs or any other institute of India.

At any B school, there is so much to do but you don't have the time for everything. It is very important to know your priorities. And this need not be same for everyone. For some sports is important, some like to read etc. While you have to ensure you spend time on academics every day it is also important you pursue your interests. Prior preparation for classes, attending classes regularly, listening attentively helps to save a lot of time during exams, quizzes etc. Do not try to procrastinate works which will end up burdening you in the end. Do not get influenced by what your friends are doing because they might have different priorities than you. Also, make sure you take some time to spend on your hobbies etc which will act as stress busters. Engage in activities which genuinely interest you. This way you are not tired working. And try to get enough sleep so that your mind is fresh in the class.

First, decide yourself what you want to do MBA or job, because if you are planning for a good college then I would rather suggest you to study for CAT exam with complete dedication of taking admission this year. CAT needs a lot of practice and study to get admission in good colleges. If you waste time in deciding these confusions you will not able to give CAT exam at good stage. So I would suggest start preparing for CAT entrance exam with complete dedication and Self-motivation. Then if you get a very good score go for TOP MBA colleges to complete your goal and if unfortunately you couldn't able to crack CAT exam then you can go for any suitable job for one year then you will have time and you can prepare will for next CAT exam.
While doing your final year you will have a flow of study for CAT and at least you will not waste a year for preparation of CAT.

IIMs are the best in the world. No B-schools abroad are nearer to the standards of Indian Institute of Management.
IIM-A, B, C are very famous. When we look into the teaching methodology the practices followed by these institutions are as follows:
1. Updating of course curriculum - The course curriculum or the knowledge imparted in IIMs is always new.
2. Live industry interaction- Industry oriented training helps students gain more practical knowledge.
3 Tie ups - Tie-ups with major companies is another important factor for the stability of IIMs.
4 Faculties-National and international faculties are taking classes in IIMs.
5. Industry experts- Experts from industry always interact with IIM students.
6. Live case study- Case study helps student know more about the real life problems faced by a company.
These are the differences between IIMs and international B-schools.