You asked
Can I adapt the ttartisan 11mm f 2 8 fisheye to canon rf?
Here is what the site says about that.
From TTArtisan 11mm f/2.8 Fisheye: TTArtisan 11mm f/2.8 Fisheye: A prime lens by TTArtisan for Full frame cameras, 11mm f/2.8. Specs - Maker: TTArtisan - Focal length: 11mm (prime) - Maximum aperture: f/2.8 - Made for: Full frame sensors - Mounts: Sony E, Nikon Z, Canon RF, L-Mount, Leica M, Canon EF, Nikon F - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Sony E, Nikon Z, Canon RF, L-Mount, Leica M, ...
From Lenses: Adapters: Mirrorless mounts are shallow, so old manual-focus lenses from film cameras adapt easily and cheaply. It's a fun way to try fast or unusual lenses, without autofocus.
Quoted from this site's pages.