Hi, You have not mentioned any specialization and even the college you want to take admission in. Assuming in general you are looking for interview rounds as this is an important phase of selection for admission to business schools.

When you prepare yourself for a face to face conversation work on Personal Introduction, Verbal Communication, Body Language, Eye Contact, Speech, Opening statements, Content. All these points are marked so they are crucial. 

Improve your communication skills, Start conversing in English. Start writing, as most colleges prefer WAT. So you can apply the above tips to improve overall. Good Luck.