Pardon my typing - I had the caps lock on!
We are not deaf overhere, so why the loud capitals?
In the absence of more detail in your question, the short answer is yes.
Most template-based maps won't display anything in the Gantt view when they are first created. However, after you add task information to a map based on a project management or other relevant template in MindManager (or any template, for that matter) these tasks should appear in the Gantt view.
Just to clarify, task information has to include as a minimum start and due dates for the task to appear in the Gantt chart. And as far as I can tell roll-up isn't enabled in any of the templates and has to be added by the user if they want it to appear.