If you are staying in Bochum for a longer period, you should start looking for accommodation well in advance.
By the way: If you haven't found a suitable flat in Bochum, you can also look in neighbouring cities such as Herne, Witten, Hattingen, Essen or Dortmund. The good public transport connections in the Ruhr region make commuting possible.
RUB AStA has created a housing exchange portal on their website. There, you can search and place an advert:
Offline
You can find flat listings in various newspapers, incl. the "Westdeutsche Allgemeine Zeitung" WAZ, and the local "Stadtspiegel Bochum" (The "Stadtspiegel" is distributed to all residents of Bochum on Wednesdays and Saturdays and displayed in various public places).
It can also be worthwhile taking a look at the various bulletin boards in the cafeteria and departmental buildings on campus.
Online
The large national accommodation marketplaces have a wide range of offers and many filter options. Some of the largest platforms are listed on "Immobilienportale".
Specialised housing websites such as portals for shared living in WGs (Wohngemeinschaft) or for temporary rentals (Zwischenmiete) can be especially helpful.
One could also find a suitable solution on social media platforms by searching for relevant key terms.
The city of Bochum as well as local housing associations and cooperatives also list housing opportunities on their websites.
Having trouble finding a suitable apartment in Bochum?
Tip: Look in neighboring cities Herne, Witten, Hattingen, Essen and Dortmund. Because the Ruhr area is so well connected, commuting to Bochum from these neighboring cities is easy.