In order for you to play Tropico 6 on macOS with minimal graphics settings, your computer must meet the following requirements
Operating System:
MacOS Mojave (10.14)
Processor (CPU):
Quad-Core (i5 or i7) 3GHz or better
Memory (RAM):
8 GB RAM
Graphics Card:
Metal, Shader 5 compliant GPU with 2GB VRam (AMD Radeon Rx560 Pro / Nvidia Geforce GTX775 or better)
Storage:
16 GB available space