We identify known TNOs and Centaurs in the complete Dark Energy Survey (DES) year six catalogue with the help of the Sky Body Tracker (SkyBoT) tool. A total of 217 such objects present at least three observations in each of the DES bands, from which absolute magnitudes () and phase slopes () are obtained to each of them (). The unknown photometric rotational variation of these bodies are considered in the determination of the absolute magnitudes, phase slopes and their respective uncertainties. We finally retain 144 objects –137 TNOs and 7 Centaurs – after applying a filter that eliminated any color () outside the interval (−2.5 : +2.5) and any outside the interval (−0.5 : +0.5). Colors , and are used to obtain, in a iterative way, the four group taxonomical classification. Most of these objects have no such classification in the literature. We determine the diameter of all these objects by combining the absolute magnitudes with average albedos for different dynamic groups. Possible connections involving colors, orbital parameters, dynamical classes and sizes are also presented. The results of this work are under review by the DES Collaboration.