Hello Subodh Gupta,
You need to define a context menu
for your application. Please note that there are two context menus - Telerik one and the standard one. The standard one is set using the ContextMenu property of every control so do not use that property but follow the help article from the link above.
We cannot reproduce the second issue. Please open a support ticket so that you can attach files and send us your application. I am looking forward to helping you further on that.
All the best,
the Telerik team