Hi Vinita,
Please check if a purchasing group is assigned to the entry channel that you have created.
Goto the responsibility Tab of a purchasing group and assign the entry channel`s Org ID or the PI users Position ID in the Organizational responsibility area of a purchasing group.
Regarding the connectivity :
The moment you save the PR in ECC, PurchaseRequestERPSourcingRequest_out interface will be triggered and the data is send to PI. Since XI adapter is used to send the data to SRM a user name and password or an HTTP RFC destination have to be maintained in the outbound communication channel.
If User name and password is maintained in the PI Outbound communication channel then the same user ID have to be added to the SRM org structure( Entry channel).
If HTTP rfc destination is used in the PI outbound communication channel then the user maintained in the RFC destination have to be added to the SRM org structure( Entry channel) .
Create a Org unit in the org structure with a name Entry channel( can be different as well) and the org Id of Entry channel or the Position ID of the RFC user have to be added to the Organizational responsibility area of a purchasing group.
Regards,
Suresh