I want to write about a personal accomplishment that I did in the field of business for a petition to Kelly School of Business but I feel that it may be general

Yes, you can write about non-school based accomplishments in your Kelley Direct Admit petition. You have missed the priority deadline though, so direct admission petitions are evaluated on a case by case basis now…so get the petition in ASAP.

Have you already submitted your app to IU?