It was part of the field artillery, and complemented the Gribeauval system.
The canon de 6 système An XI was used extensively during the Napoleonic Wars.
It was considered as a good intermediate between the Canon de 8 Gribeauval, considered to be too heavy for field artillery, and the Canon de 4 Gribeauval, considered as too light and lacking striking power.
[1] One of the characteristics of the Canon de 6 is that its design is even simpler than that of the Gribeauval cannons, as it lacks reinforcing mould rings, except for the one before the muzzle.
[2] Media related to Canon de 6 système An XI at Wikimedia Commons