Hello Manas,
Yes, you can do this. I would suggest you to use RadWindow for this, because it encapsulates functionality like dragging the popup, resizing, minimizing, maximizing, etc. If you don't need all these features, you can use the Silverlight Popup control or the Silverlight 3 ChildWindow control.
Hope this helps.
Regards,
Miroslav Nedyalkov
the Telerik team