.net core 3.1 is supported on Mac via Rosetta via the lastest o/s upgrades (Apple supplied a Rosetta fix for core 3.1).
.net 6 will be the first to produce a Mac arm image. Universal image support may come next year with .net 7. This means you can not publish to the Mac App Store. IOS apps are fully supported as in the past and they can be published.
Visual studio code runs native on Mac arm, and Mac visual studio has been updated to run on Rosetta. Debugging native arm is still a work in progress, but coming along.