When i select simulator from xcode 6 then i\'m getting multiple option to select simulator but simulator comes with UDID. Please see the below image and please help me out.
In Xcode, go to Window -> Devices (shortcut is Cmd+!)
In the left pane, delete all the superfluous simulator devices (select in the left pane and press delete on keyboard)
Usually these are the ones that have no OS (showing iOS: n/a).
This usually happens when you try and copy older simulator versions directly in the SDK folders rather than installing them from Xcode -> Preferences.