Hello Venkatesh,

Thank you for posting in the community.

In this scenario I would suggest firstly converting your existing datatable to a list in order to prepare it for being used as the source of an igOlapFlatDatasource. A discussion which may be helpful in that respect may be found at:

http://stackoverflow.com/questions/1427484/convert-datatable-to-list

Consequently, when a List version of the DataTable is available I suggest following the guidelines specified in our documentation at:

http://help.infragistics.com/Help/NetAdvantage/jQuery/2013.1/CLR4.0/html/igOlapFlatDataSource_Adding_Using_MVC_Helper.html

Please do not hesitate to contact me if you need more information.