Canon 5DS R has a Canon EF lens mount and currently there are 257 native lenses available for this mount.
The latest released lenses that are compatible with the 5DS R are the Carl Zeiss Makro-Planar T2/50, the Canon 50mm f2.5 Macro and the Canon MP-E 65mm f2.5 1-5x Macro.
Canon 5DS R doesn't have a sensor based image stabilization system but 77 of these lenses already comes with optical image stabilization.
Since Canon 5DS R has a Full frame sensor, it has a focal length multiplier of 1x so lenses will provide their original focal length on 5DS R.
You may also also be interested in these:
Canon 5DS R Lenses with Image Stabilization
Canon 5DS R Lenses with Weather Sealings