Hi Raj Sharma,
RadTreeView drag and drop methods do not support arbitrary objects, they only support drag and drop between RadTreeViews and inside a RadTreeView itself. The standard .NET drag and drop and RadTreeView mechanism are mutually exclusive which means that you will have to choose only one and tailor your application toward it. Please write again if you have other questions.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items.