It depends on college you are looking for. Each IIM has different criteria. Work experience is recommended but not mandatory for selection. Though some IIM's give some weight age to relevant work experience ranging from 5 to 10 percent.

You may always highlight following during your interview:

    Internships
    Professional projects during school/undergrad
    Extra curricular social work

This will be strengthen of your profile.Just make sure to maintain a decent academic profile & great CAT score, which is all that is required to get an edge over your competitors.

Good Luck!