Most of my shapefile's attribute table are in arabic and on the tooltips, text are displaying in different characters which cant be read...please advise me what to do to resolve this
As in the SL API there is no out-of-the-box functionalities to display shapefiles, we would need more infos about your process: How do you display your shapefiles? What kind of error do you run into?
I'm using Vishcious.ArcGIS.SLContrib to add graphics from shapefile using openfiledialogue. Even if I access through mapserver service, I'm facing the same issue as not displaying the arabic data.
I am still not sure to understand your process, but from the screenshots you attached, your issue doesn't seem to be related to Silverlight. It looks more like an ArcGIS Desktop or ArcGIS server issue. You may have more chance to get an answer by posting your questions on the these forums.