Seiko’s 6R family of movements is an upscale line for higher-end watches. Launched in 2006, Cal. 6R15 was a modification of the mainstream 7S family but with better finishing and a Spron 510 mainspring. Seiko later created Cal. 6R20 and other movements with modules on the 6R15 and a Hi-Beat 28,800 A/h escapement. These movements also add hacking and hand winding as on the derived 4R family.
In 2019, Seiko revisited the aging 6R family, adding the new Cal. 6R35. A simple movement like Cal. 6R15, it operates at 21,600 A/h and has only a date complication. It adds one additional jewel, however, and boasts a 70 hour power reserve.
| Jewels | Components | Speed | Power | 3:00 | 6:00 | 9:00 | |
| 6R15 | 23 | 168 | 21,600 | 50 | Date Window | ||
| 6R20 | 29 | 208 | 28,800 | 45 | Day Subdial | Date Subdial | Clockwise Power Reserve |
| 6R21 | 29 | 208 | 28,800 | 45 | Day Subdial | Date Subdial | Counter-Clockwise Power Reserve |
| 6R24 | 31 | 224 | 28,800 | 45 | Retrograde Day | Retrograde Date | Clockwise Power Reserve |
| 6R27 | 29 | 28,800 | 45 | Date Subdial | Counter-Clockwise Power Reserve | ||
| 6R35 | 24 | 21,600 | 70 | Date Window |