You can download the community edition of Jaspersoft Studio 6.8.0 from reputable archives:
The 6.8.0 release brought several technical enhancements and dependency upgrades to improve the reporting workflow: Download -UPD- Jaspersoft Studio 6.8.0
Because official links on TIBCO (now Cloud Software Group) often redirect to the latest version, finding the exact 6.8.0 installer can be tricky. Follow these steps carefully. You can download the community edition of Jaspersoft