Can you install macOS 10.15 Catalina on Mac Pro (tower, 2012)?

If the software-updater (app-store or System Preferences, depending the running OS version) says so, I'd say so, too.

There are compatibility-charts around to be searched and found.

Be aware that not every mac digests the newest OS very well. If your mac is running on low RAM/"slow" CPU, you may be disappointed.

hth

david

Officially you can't.

But there are ways search for Catalina on unsupported Macs.