It seems you're looking for content related to a download. However, there is no official software or file called "3D System Shader Model 60." You likely mean Shader Model 6.0 (often written as SM6.0), which is a feature level for DirectX 12 and Direct3D 12.
There is no offline installer specifically for "Shader Model 6.0." The closest you can get is the DirectX 12 offline redistributable (part of the Windows SDK), but that is intended for developers, not end-users. For normal users, GPU drivers + Windows Update is the only safe path. 3d system shader model 60 download full