Thanks Rakshit for the reply.
Custom coding can be done once we are able to receive the data at the script level.
For that the OData model has to be compatible with XML/OData data meaning the OData xml that I will pass to Integration gateway it should be acceptable to Integration gateway.
If my above understanding is correct I need to find out what OData model I can create using Eclipse and deploy and what would the format for the OData xml that I can post to the Integration gateway so that it is received in the Request method where I can modify the same using custom scripting.
Please let me know if my understanding is incorrect.