Hi Shree, to get into any of the three colleges mentioned above, you need to strive hard and prepare well for the CAT exams. All the three colleges accept CAT Scores only.

The CAT exam consists of three sections namely, 

1) Verbal Ability and Reading Comprehension

2) Data Interpretation and Logical Reasoning

3) Quantitative Ability 

One needs to score more than 150/300 on a minimum scale to get 99+ percentile and a score of 130+ for a 95+ percentile and a score of around 105+ for 90+ percentile. However I have mentioned it on a raw analysis. It varies every year based on various criterias.

The top of all the three colleges is IIM and it has older, new, newer IIMs for which a minimum of 90 percentile is required. 

The older IIMs like Ahmedabad, Bangalore, Calcutta expect around 98+ percentile, whereas Indore, Kozhikode and Kanpur expect around 96+ percentile. The new IIMs like Lucknow, Trichy etc. Expect around 93-94 percentile and the new ones like Jammu Kashmir expect around 88-90+ percentiles.

Next comes JBIMS, which is a top college in Mumbai domicile and top 10 colleges of India. They expect a CAT cutoff of 95+ percentile. It is the best Return of Investments colleges in India, wherein the fees is low amd placement is very high. 

FORE is third of the list, which is a good college which expects a percentile of around 85+ in CAT exams. 

CAT exam is one of the toughest exams, which not only requires hard work, but lot of practise and smart work to ace. A lot of mock exams need to be taken and good analysis needs to be done for the mock exams. 

For IIMs you need to apply separately, you apply for them during the CAT application form filling itself. But for the other two colleges, you need to apply separately with the CAT scores. 

After getting selected via CAT scores, you need to ace the GD-PI rounds of the respective colleges and the cummulative performance of all along with your academic scores and work experience, provide you admission to the colleges. All the best !!!