If you need a visa to study at Thomas More, you will need to apply for a long-stay visa (type D). This is also called an Authorisation for Provisional Sojourn (Machtiging tot Voorlopig Verblijf). It allows the holder to enter and remain in Belgium for a period longer than 90 days.
Students should not enter Belgium on a tourist visa if they intend to stay longer than 90 days. Thomas More will not support an application for a change of status or visa.