You should be aware that the selection process of IMI Delhi is quite stringent. IMI Delhi is ranked 14th position among the top B schools in India, and its selection process is different from other top B schools. They give less weightage to your CAT score and have an extempore round as well. This round is not so difficult, but it may vary according to your profile, as they want a diverse background in their institute. They try to test your overall personality by checking your academics, team spirit, leadership, communication skills, how you react to a given situation, and many other small tests to decide whether you are eligible for their college or not.
It's important to note that every top college wants the best students to become future leaders in the corporate world, but luck also plays a role in the selection process. If your academic score is not good, but you impress them with some other talent you have, they will not deny you admission because they want diversity.
In a nutshell, most of the top 30 colleges do an overall screening before admitting students because they want the best in you. Therefore, if you want to get into a top B-school like IMI Delhi, you should work on developing your overall personality and showcasing your talents apart from good academics and a CAT score.