The most common reason for missing SM 6.0 support is an outdated driver. Graphics card manufacturers regularly release updates that add or refine support for new shader models.
A: No. DirectX 12 is the API; Shader Model 6.0 is a feature of DirectX 12. You can have DirectX 12 and still only support Shader Model 5.1 (e.g., on some older DX12-capable GPUs). Shader Model 6.0 Download Windows 10
To utilize Shader Model 6.0 on Windows 10, your system must meet three specific criteria: The most common reason for missing SM 6
If your GPU is from 2012 or earlier (e.g., GTX 600 series, HD 7000 series), SM 6.0 will not work—even after updating Windows. In that case, no software “download” can help. You need a hardware upgrade. DirectX 12 is the API; Shader Model 6
If you are a developer looking to compile shaders using Shader Model 6.0: Shader Model 6 · microsoft/DirectXTK12 Wiki - GitHub