Is this program compatible with Mac 10.6.8?
Yes, the software is compatible with Mac 10.6.8. I have checked the Product Specs page provided by the developers, and it appears that Fisheye Fixer requires OS X v10.6.1 or better. Since you have Mac 10.6.8, the software is fully compatible with the operating system installed on your Mac.
You can get more information using the following link: http://www.crumplepop.com/gopro-fisheye-correction/