| Company name | Reg. code |
|---|---|
| DRR HOLDING OÜ kustutatud (former name DRR Holding UÜ) | 14026635 |
| DRRM HOLDING OÜ | 14108132 |
| DRS HOLDING OÜ | 16400428 |
| MRR45 HOLDING OÜ (former name MetRem OÜ) | 14342081 |
| RRR HOLDINGS OÜ | 16384066 |
| ORR HOLDINGS OÜ | 17408432 |
| SMT HOLDING OÜ (former name DAR Holding OÜ) | 14261307 |
| AIRION TECHNOLOGIES OÜ (former name RR Holding & Management OÜ) | 17179440 |