how can i collect multiple reprots into one report?
There are two main options available to do something like this:
1) You could leverage subreports to create a report with multiple charts, tables, etc. - this is possible using Jaspersoft Studio
2) If you are a commercial server customer, there is dashboard functionality in the server that allows you to brows the repository for reports that you have created and add them to a dashboard by dragging and dropping the reports onto a canvas, etc.
I hope this helps.