Hi Sanket Singhvi,
In order to allow dragging outside your application or outside the element host you need to enable native drag mode to our raddraganddropmanager. To do that you need to add the following code:
RadDragAndDropManager.EnableNativeDrag = true;
This has to be set once, preferably on application start (or app constrictor in wpf apps) or before initialize component of the wpf view.
Let me know if you need any further assistance.
the Telerik team
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