Hi Wasim,
With respect to your requirement.
1. You need to create Single Project as HDFC and Different Branches has WBS element, here you can attach network to each WBS element, so the cost can be calculated individually.
2. You need develop HDFC Branches has your WBS elements and attach networks to it. Here you will be creating multiple projects.
The design is based on the role who is going to use SAP PS.
If i am a customer who is gng to do projects for HDFC, i prefer first option, since i can individually calculate the cost based on branch location using WBS element.
Regards
Terence