Pawan,
You are on the right track with the picture you attached. You need add more of the Add Locations tools to connect each of your orders, routes, etc to the Vehicle Routing Layer. You already do that for the Depots. Once all of them are attached, then call Solve on the last VRP layer.
Also you may want to post such questions to the appropriate forum (e.g., the network analyst forum or the geoprocessing forum and not the data model forum for better response.
Regards,
Jay Sandhu