There is no full DirectX support inside containers on PVC for Windows, as containers has no access to video and audio hardware since Parallels Virtuozzo Containers is OS virtualization solution.
By default DirectX will be present inside the container as a part of OS. You may check the DirectX version from the inside of the container by calling usual "dxdiag" utility:
Start >> Run >> dxdiag
However, certain applications requiring DirectX may not work if they use APIs for direct access to the video or audio hardware.
On the other hand, if application only uses some of DirectX libraries or capable of working with redirected audio device, such applications may work correctly.