Hi Nithin,

When using the Standalone Report Designer, the executable file must have a reference to your business logic. This is accomplished by modifying the configuration file in the same folder as the Report Designer. Your custom business logic should be contained within a single compiled assembly that exposes public data accessor methods. A copy of that compiled assembly should be added to the same directory as the Report Designer. The ObjectDataSource within your Report will then have access to the public data methods.

Additional Information:
Standalone Report Designer - Default Configuration

Regards,
Rick
Progress Telerik