If the server runs under Windows, R-Drive Image accesses all hardware through the system drivers. Obviously, the Windows version of R-Drive Image will work with the controller.
It's better to test the startup version of R-Drive Image directly on the server. R-Drive Image has a 30-day full-functioning trial period, so it's a good idea to try it. Actually, you don't have to do anything that may put the data on the server at risk. If you just start the server with the startup version, and it sees the volume on the controller, most likely the startup version of R-Drive Image will work with it normally.