I was accepted into MSU but have not heard back from UMich, and I was wondering if someone I would be able to place my deposit for MSU in order to reserve my spot just in case, but go to UofM if I end up being accepted

You can deposit at MSU, but if you were to get into U Mich and choose to attend, you would have to put down another deposit to U Mich and forfeit your deposit to MSU.

Is the issue that you need to deposit to reserve dorm space?
If not, I suggest waiting until you hear back from U Mich. Less than two weeks to go.