Yes, GNS3 works on Mac. In fact, it works on most major operating systems, including Windows, Linux and macOS.
GNS3 is a network simulator that allows you to create complex network topologies and run virtualized versions of real devices - such as routers, switches and firewalls - in a simulated environment. This makes GNS3 an invaluable tool for networking professionals who need to test out configurations or troubleshoot problems in a safe and controlled environment.
One of the great things about GNS3 is that it's free and open source, so anyone can use it. There's also a huge community of users who are always willing to help out if you get stuck.
If you're interested in trying out GNS3, head over to the website and download the software. Then check out some of the excellent tutorials on YouTube or the official documentation to get started.