The version of the content package is okay; the content files have not been updated since the original launch of TZR, so hence their having that version number. No worries! We almost never update expansion content files after a release.
In terms of the actual code and language files and so forth, those have been updated repeatedly for years for TZR, and all of that is contained in the main code installation. If you have version 6.0 installed, or update to that via the in-game updater, your version of TZR's code and language files are included in that (and are NOT included in the content installer, which is just images and music).
TLDR: Install that content pack, and update the game (if needed) via the in-game updater, and you're all good!
Hope that helps!