Hello Murali Karlapudi,
Please, review the following forum post, where this question is already answered:
http://www.telerik.com/community/forums/silverlight/chart/is-it-possible-to-annotate-customgridlines.aspx
I hope these direction will help you to achieve the desired effect. If further questions arise, do let us know.
Greetings,
Polina
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?
Explore the
Telerik Public Issue Tracking
system and vote to affect the priority of the items