The currently newest stable release 5.8.0 and preview release 5.9.0 for Windows do not support UKFTractography. I downloaded both versions and then downloaded extension SlicerDMRI, but I get the following error message: “slicerDMRI depends on the following extensions, which could not be found.” And there is no UKFTractography extension available.
However, I tried the older release 5.6.2 and this one has both SlicerDMRI and UKFTractography extensions.