DirectX 11 Supports Ray Tracing (DXR)?

yimx said:
Or should I choose Directx12 for ray tracing?

Yes. Ray tracing only works with DX12 or Vulkan.

You can write your ray tracer with shaders in dx11 or opengl, or it can be implemented it in opencl.
But it will not use nvidias dedicated shader cores. But probably they will get thrown out eventually from the chip anyway due to the lack of interest.
It makes no sense to change an api for such nonsensical features.