Hello satish,
The following help article demonstrates how to pass a string from a RadWindow to its parent:
http://www.telerik.com/help/silverlight/radwindow-using-user-control-with-radwindow.html
You could use the same approach, but instead of the PromptResult, you could use the Tag property of RadWindow to pass any object you want.
Greetings,
Valeri Hristov
the Telerik team