RVsitebuilder provides 2 platforms for you to build website.
You can have a quick look for what version yours is.
1. By the icon you access from cPanel control panel.
2. By content editor you're working with.
RVsitebuilder 7 content editor
RVsitebuilder 6 content editor
3. Current version of your RVsitebuilder
Your current version of RVsitebuilder 7 is at App Launcher -> Manage.
Your current version of RVsitebuilder 6 is at "My Site" tab, at the bottom.