Well, it's great if it works now

As for ROIs, the current interface allows you to filter the full brain tractography by delineated ROIs that you import using the bottom part of the diffusion interface. They have to be overlaid on the DTI image.
There exist some white matter atlases in the literature (Catani, ICBM) that could provide you with pre-delineated ROIs. You would need to register them to your image of course.