You can manage your Office 365 ProPlus subscriptions online through your UT Microsoft Organizational account. From the management interface, you'll be able to see how many devices you have installed the software on and deactivate any licenses that are no longer in use. You are allotted a total of 5 licenses.
You can use the direct URL of https://portal.office.com/Account#installs to see your active installations.
Or, you may follow the steps below at http://office365.utk.edu to see your active installations.