Regensburg is a city that is very popular with tourists from all over the world. Accordingly, there are many hotels to suit all tastes and budgets, from 2-star hotels to 5-star luxury. Unfortunately, there is no hotel that is particularly close to the OTH University of Applied Sciences as a venue. However, almost everything in Regensburg is within walking distance or a short bus journey away.
We would therefore not like to recommend a specific hotel, but advise you to orientate yourself towards the old town and the railway station. Here is a map of some important Regensburg landmarks and in particular some places that may be relevant for the BVM depending on the activities you are taking part in: https://www.bvm-conf.org/campus-and-city-plan/
Nevertheless, the Hotel Herzogshof deserves a special mention because it is located right next to the Herzogssaal, where the social evening will take place. And because you get a discount if you mention "OTH-Veranstaltung" when booking: https://herzogshof.com/
The Regensburg tourist office has put together some portals for hotel bookings: https://tourismus.regensburg.de/en/your-stay-in-regensburg/portal-of-choice
We would particularly like to recommend https://hotels-in-regensburg.com/en, because this portal is operated by some Regensburg hotels themselves and therefore more profit effectively remains with the hotel than when booking via platforms such as HRS or Booking.