The CVs for IIMs are required and drafted only after a student gets the IIM call. Usually students start drafting the perfect CV a month before joining the course.

However, once into IIM the students are usually busy in refining their CV , getting the needed endorsements in their first two terms to get ready for the summer placements.

So, no urgency until then. It's better to concentrate on the task in hand i.e, CAT as this is the basic criteria for the admission. Further, the emphasis on your CV during PI is less, they put greater importance to you as an individual

Once you get the call you'll have to draft a CV, and make sure you know them well.

All the best!