Canon R1 has a Canon RF lens mount and currently there are 104 native lenses available for this mount.
The latest released lenses that are compatible with the R1 are the Brightin 14mm f2.8, the Canon RF 20-50mm F4 and the Brightin 11mm F2.8.
R1 also has a sensor based image stabilization system that is up to 8.5-stops effective which means that all of these lenses will be stabilized when used on the R1.
Since Canon R1 has a Full frame sensor, it has a focal length multiplier of 1x so lenses will provide their original focal length on R1.
You may also also be interested in these:
Canon R1 Lenses with Image Stabilization
Canon R1 Lenses with Weather Sealings