Hi Sandeep,
The information about the new features, changes and backward compatibility
issues if any for all the RadControls is available on Telerik's site, section
Products > ASP.NET AJAX Controls > What's New >
Release History. You can choose an appropriate RadControls version from the Release History where all the RadControls are listed along with the new features, changes and bug fixes that are added to the corresponding control.
Hope this helps,
Shinu.