Can VS 2015 supports Xamarin or not?

Yes VS 2015 support Xamarin.

reff the url:https://developer.xamarin.com/guides/cross-platform/windows/visual-studio/

Hope this official site,will clear all your doubts:

https://www.visualstudio.com/en-us/features/xamarin-vs.aspx

https://developer.xamarin.com/guides/cross-platform/windows/visual-studio/

Please let me know your thoughts

No issue with MSDN there or not there.

VS 2015 with MSDN or without MSDN?

I've query that Without MSDN, Visual Studio Not support XAMARIN ?.

Yes VS 2015 support Xamarin.