Unity Editor System Requirements
This section lists the minimum requirements to run the Unity Editor. Actual performance and rendering quality may vary depending on the complexity of your project.
Windows:
Windows 7 (SP1+) and Windows 10, 64-bit versions only
X64 architecture with SSE2 instruction set support
DX10, DX11, and DX12-capable GPUs
Mac Os:
Sierra 10.12.6+
X64 architecture with SSE2 instruction set support
Metal-capable Intel and AMD GPUs
Here is the link to download UNITY from their site: