If I install xcode 6 will it overwrite my Xcode 5?
Also will I still be able to publish apps using Xcode 5 if it doesn't overwrite it?
Will I be able to publish apps using Xcode 6 too?
If I install xcode 6 will it overwrite my Xcode 5?
Also will I still be able to publish apps using Xcode 5 if it doesn't overwrite it?
Will I be able to publish apps using Xcode 6 too?
Xcode is simply a drag & drop install, which means you can choose to replace Xcode 5 with it OR you can have Xcode 6 live side by side with Xcode 5.
Apple hasn't mandated to submit apps using Xcode 6 yet, but eventually they will, probably once Xcode 6 leaves "beta" status.
Xcode 5 will still be present on the system you're using, and Xcode 6 is able to publish apps the same way as Xcode 5.
Michael Dautermann is right. You can install or keep xcode 6 beside xcode 5.
You should use xcode 5 to publish app.