Due to the Corona virus, the town hall cannot be visited until April 19.
You can join a guided tour in the Town hall every day. The tour lasts 1 hour and starts at the Tourist Information Centre. The language of the tour varies from day tot day and is indicated next to the date you choose.
Groups as of 10 people make a separate reservation. All informations can be found here: https://www.visitleuven.be/en/town-hall.