6 Medium Brigade was re-designated 6 Medium Regiment RA in May 1938. The Regiment was disbanded in January 1940 and re-formed in September with four batteries. It served in India and Burma under several different Indian formations. In April 1947, 6 Medium Regiment RA was re-designated 18 Medium Regiment RA with 18 and 52 Batteries.
Illustrations of the formation badges under which a unit served or supported are given. This is no guarantee that the unit used this formations badge.
| Sep 39 | Dehli Area | India | |
| Jan 40 | Disbanded | ||
| Sep 40 | Reformed | Cambellpore, India | |
| Mar 42 |  |
23 Indian Division | Ranchi, India |
| May 42 | 36 Indian Infantry Brigade | India | |
| Sep 42 |  |
15 Indian Corps | India |
| Sep 43 |  |
26 Indian Division | Chittagong, Bangladesh |
| May 44 | |
26 Indian Division | India |
| Oct 44 | |
15 Indian Corps | Arakan, Burma (Myanmar) |
| Jun 45 | 59 Army Group RA | Secunderabad, India |
Batteries
| Sep 39 | 18, 19, 23/24 |
| Sep 40 | 18 (Quebec), 19 (Niagra), 23/24, 245 |
| May 41 | 18, 23/24, 245 19 Battery to Iraq |
| Feb 44 | 18, 19, 23/24 245 Battery renamed 19 Battery |
| Jan 45 | 18, 19, 23 |
Equipment
| 1944 | 5.5 inch guns & 7.2 inch Howitzers |