I am working on a mac (os 10.9.5) and have reaper 4.74 and the way I get it to track/reamp is as follows:

0. Set the 11r as your interface
1. Have a dry guitar (or bass) track recorded from input 1 (guitar input), we will call that Trk1.
2. On Trk1 click on the 'I/O' button that is next to the track name and select the 'Add new hardware output' -> 'Output 3' (or 3 and 4 if it is a stereo track), my output 3 is called 'ReAmp L'.
3. Hold down the 'Edit/Back' button on the 11r and select 'Rig Input'. Switch it to 'Re-Amp'.
4. Make a new stereo track (Trk2) in reaper and set its input to 'Input 3 + 4', on mine it is called 'Eleven Rig L + Eleven Rig R'. Name Trk2 with the patch selected, record enable and mute Trk2.
5. Make sure Trk1 is NOT record enabled or muted.
6. Press record on reaper, you should hear and see the track being printed.
7. Check the time-alignment of the audio on Trk2 (sometimes mine end up a few milliseconds late, based on my system's performance).
8. Repeat steps 4 through 7 to do multiple different 11r presets.
9. When done, remember to hold down the 'Edit/Back' button on the 11r, select 'Rig Input' and set it back to guitar.

I hope this works for you, post back if you run in to problems.