The Carillon garrison commander is a Cylon Centurion who commands the Cylon forces that operate clandestinely on Carillon.
After ersatz Colonial Warriors fill the chancery for the Gold Cluster award ceremony officiated by Sire Uri, Seetol reports to it that over 200 Warriors are in attendance. This allows the Cylons to believe that the Fleet is defenseless, and spring their ultimately ill-fated attack on the surviving Colonials (TOS: "Saga of a Star World").
The fate of the garrison commander is unknown, but likely destroyed along with the Cylon forces there.