In order for you to play Dota 2 on macOS with minimal graphics settings, your computer must meet the following requirements
Operating System:
macOS 10.13.6 or newer
Processor (CPU):
Dual core from Intel
Memory (RAM):
4 GB RAM
Graphics Card:
Metal-capable GPU (AMD GCN-based GPU or newer, NVIDIA Kepler-based GPU or newer, Intel HD 4000 or newer)
Network:
Broadband Internet connection
Storage:
60 GB available space