Hi Ravindran,
Yes, there is full integration between PMR and ECC for offer execution, including price promotion creation.
Here is the path to the Consultant Learning Map:
-> Go to the SAP Support Portal (service.sap.com)
-> Go to the "Knowledge Exchange" tab
-> Click "Ramp Up Knowledge Transfer"
-> Scroll along the left to SAP for Retail
-> Click SAP Trade Delivery 2010/2011
-> Click SAP Promotion Management 7.1 and proceed through the learning map