Hi Jagannath,
I assume you have an asynchronous interface?
In that case you have to generate the inbound proxy in your application system. In the proxy class' method call /AIF/CL_ENABLER_PROXY=>PRCOESS_MESSAGE. Pass the input parameter of the proxy's method as well as the name of the exception class to PROCESS_MESSAGE.
Then create an AIF interface. Go to transaction /AIF/CUST. And create a namespace in Define Namespace (if not already done). Go to Define Interface, create a new interface. Maintaine your inbound proxy class an press enter the fields raw data structure and record type should be filled automatically. Maintain your destination structure in field SAP Data structure. Save. Then you can start to map your source structure to your destination structure to in Define Structure Mapping.
Those a basically the first steps for the inbound interface. For more information you could have a look into the AIF cookbook http://scn.sap.com/docs/DOC-34037
For your outbound interface also have to generate a proxy. And create an AIF interface, but maintain the outbound proxy class name. To trigger AIF you can call function module /AIF/SEND_WITH_PROXY. For the outbound intereface you can find more info in following document http://scn.sap.com/docs/DOC-45728
Best regards,
Verena