You can see the operating system version, i.e. the macOS version, by clicking on the Apple menu and selecting About this Mac. Three newest operation systems are supported versions. Read more from Apple Support.
MacOS Catalina 10.15 was released on October 7th, 2019. This version is not yet fully compatible with all University of Helsinki services. Likewise all Software Center applications are not yet compatible with Catalina 10.15. Centrally maintained University of Helsinki computers will be updated according to a schedule determined after testing.