Hi Shailendra,
There is built in methods available from crystal report to convert it into different formats
After binding your crystal report below is the code for exporting it into pdf format.
ExportOptions exportOpts = doc.ExportOptions;
exportOpts.ExportFormatType = ExportFormatType.PortableDocFormat;
exportOpts.ExportDestinationType = ExportDestinationType.DiskFile;
exportOpts.DestinationOptions = new DiskFileDestinationOptions();
DiskFileDestinationOptions diskOpts = new DiskFileDestinationOptions();
( ( DiskFileDestinationOptions )doc.ExportOptions.DestinationOptions ).DiskFileName = Server.MapPath("fin.pdf");
doc.Export();
Response.Write(dt.Rows.Count);
Response.Write("<a href=\"" + pdfFile + "\">" + pdfFile + "</a>"
);
If you want to provide selection of export format there is built in option in crystal report viewer.
Hope this helps