Hi everyone ! I was trying to learn directx and on the internet I have found some reasonably good tutorials on it.
But I am a little bit confuse between the versions of directx , a tutorial at http://directxtutorial.com has tutorials on these 3 versions but dx 11.1 and 11.2 are based upon winRT and dx 11 seems to be based upon Win32 so are dx 11.1 and 11.2 more higher level than dx 11? Is the performance same on these APIs?

DirectX 11 is a family of APIs.

11.0 is supported on Vista+ (via a Service Pack on Vista). DX 11.1 is only fully supported on Win8+, though some portions of 11.1 have been back-ported to Win7. DX 11.2 requires Win8.1+.

Newer versions just add new features. Some of those features allow better performance if you use them properly, but the core performance of the API is the same (i.e., DX 11.2 support won't suddenly make old DX 11.0 code faster). There's not really anything you can draw on screen with DX 11.2 that you couldn't draw with 11.0 (or 9, for that matter), though if you're really (_really_) pushing the boundaries of modern rendering you may find a huge value in the DX 11.2 features.

TL;DR: the version of DX you use is more about about which OSes you want to release your game on than anything else.

DirectX was an independent feature way back 15 years ago.

Today, DirectX is an OS component.

If you target Windows 7 you get DX11. You can also use older API versions.

If you target Windows 8 you get DX11.1. You can also use older API versions.

If you target Windows 8.1 you get DX11.2. You can also use older API versions.

If you target Windows 10 you get DX12. You can also use older API versions.