If the camera was properly set up when shooting on Red, it will have both the “base rate” and the “record rate” where “Base Rate” is the intended playback speed, or project rate. So assuming that the base rate is 23.976 and the record rate was 96fps (95.094fps) it would automatically play back as a 4x slomo. Same for a record rate of 12fos, it will play back twice as fast.
Once in the timeline, you will now have everything at 23.976 with clips at native rate or sped up or slowed down. From there you can apply whatever additional motion effect as needed creatively. That is where you get into the discussion of Twixtor, FluidMotion, etc.
Michael