The uniqueness of IIM Ahmedabad lies in the fact that it does consider low CAT scores also unlike other IIMs. One of my brother's friends got selected even with a percentage of 87 because of his experience as a law professional. However, the case is different for engineering students. IIMA gives less preference to them.
So I suggest you, being a BCOM student, get a good job, gain experience in the field and then pursue MBA when you have a better experience.