can we have same name of 2 dialogs in aem ?
Can you elaborate more on your requirement ?
Are you trying to have same name for 2 fields in a single dialog ? If so we cannot have same name for two fields as second will overwrite first value and only stores second.
it would be great if you tell more.
You should not use the same name in a dialog (I assume that is what you mean). As Ravi points out - you would have conflicts.
Best practice for working with dialogs and Granite can be found here - Building Experience Manager Components using Granite/Coral Resource Types