This is not really a legal question. It would be dictated by the relationship between you and the university. If they asked you to inform them of any future charges then you must do so. If they did a background check and asked you about your criminal history to that point and no written or verbal request to update with any new arrest then I don't believe you are obligated to tell them. But the utlimate decision has to be made by you weighing what is the right thing to do and the possible ramifications of handling one way or the other.
You are in a catch 22 situation and should speak with an attorney or other similar counselor about your duties and responsibilities to be candid and disclose versus your fear that disclosure will jeopardize your future. Moreover I have serious doubts that your matter will result in a diversion if your offense is in Indianapolis, Indiana (Marion County). While I rarely if ever offer or recommend that users of this forum contact me directly for a consultation, I may be in a unique position to offer some advise on your particular situation and as consultations of this type are free of charge, I would be happy to discuss your matter with you confidentially if you wish to contact my office and request a consultation.