Hi Kannan,

As you are new to our Chart control, I would suggest you to try our new ChartView control. Using below link you can find more information on how to create a pie chart:
http://www.telerik.com/help/silverlight/radchartview-series-pieseries.html

Info on how to create chart in a data bound scenario can be found here:
http://admin.telerik.com/www.telerik.com/help/silverlight/radchartview-series-databinding.html

I have also attached a sample project demonstrating the above.

In case you want to use the old chart control, you can find a lot of useful information here:
http://www.telerik.com/help/silverlight/radchart-populating-with-data-data-binding-with-manual-series-mapping.html

Hope this helps you get started.

Kind regards,
Peshito
the Telerik team