Mac - Guitar Pro 5.2

: TuxGuitar is a free, open-source editor that can open and edit .gp5 files on modern macOS.

: Use software like VMware Fusion or Parallels Desktop to install an older macOS version (like Mojave) or Windows to run the application.

If you open a modern .gp file (from GP7/8) in GP5.2, it will not work. You will need to ask someone with a new version to "Export as .gp5" for you.