Yes, you would be able to filter reports based on Tags. Please navigate to the Legacy Reports section to see all the various reporting functionalities listed based on your plan.
Open the desired report and click on the Filter button. You would find 'tags' as part of the filters (click on '+ More' to expand all the available filters) on the left side of the report. On entering the tag in the filter, it would retrieve the metrics for the tickets with that particular tag.