Hi Senthil,
SAP Enterprise Project Connection provides standard connection between SAP Project Systems and MSP/Primavera P6. This allows for bi-directional transfer of information including planned/actual costs/hours/quantities from SAP, and schedule information from the scheduling tool. Project structures such as WBS elements and networks/activities can also be synchronized between the 2 platforms, with many-to-many mapping capabilities if needed.
Commercial Project Management sits on top of Project Systems, so will have visibility into schedule data from MSP/P6. Other modules connected to Project Systems will also have information available from the schedule. For example, delivery dates for materials or resource requirements could follow the schedule as it changes in MSP/P6.
I hope this helps - please feel free to reply with any further questions!