Hi Ravi,
Before deciding to create a generic DataSource, you should evaluate the options to enhance a Business Content DataSource. It is possible to extend the extract structure with additional fields and fill them in Enhancement RSAP0001 or BAdI RSU5_SAPI_BADI.
If you would decide to go for a generic DataSource after all, then please share more details on the issue you are facing. I.e. detailed error message(s), screenshots, etc.
Best regards,
Sander