Hello Bhavya,

There are few important things one you should take care while preparing for IIMs or FMS. 

• Class 10th and 12th percentage(above 90%)
• Graduation CGPA at least above 8
• Job experiences
• CAT score

So, the gap year will not at all affect your selection in any of the top b-schools. Just take care of things mentioned above. Thought the most important part is CAT score. Also, I suggest you to get a job experience in the year you are dropping. You can also apply to diploma courses other wise it is fine to drop now.

To know the full eligibility criteria you can visit https://bschool.careers360.com/articles/iim-admission-criteria/amp

Thanks