I want to install win srv 2012 r2 in my workstation only for practice , can i install it in hp xw4600

Depends on the processor you have in the workstation.  If it is 64-bit, you might be able to install.  I say 'might' because you might need device drivers that are not part of the Windows Server installation media.  If HP provides those drivers for the workstation, then you should be able to.  If you want to run Hyper-V, it also requires the processor to support Virtualization Technology (hardware support for virtualization) and Data Execution Prevention.  Without those, Hyper-V won't install.

No matter what, though, it will not be a supported configuration, and it will require a proper license for the workstation.