What kind of objects can I create reports on?

Reports can report on data from trackers, tasks, planning folders, and repositories.

Task reports can report on data in a single project or across multiple projects. Tracker reports can report on data in a single tracker or across multiple trackers in a project or multiple projects. Task and Tracker reports are in tabular format and grouped under Table reports. You can also create reports on data in planning folders and on data in source code repositories.