Can I distribute my app developed with xCode 6.4 if there is already xCode 7

Yes, Apple typically allows us to use the previous Xcode version for submissions for quite some time after a new version is released. At the time of this writing, Xcode 5 is still allowed, for example, and that's a year or more out of date now.

You should still test your binary on iOS 9 in case something breaks, but you will most likely be able to continue to build against the iOS 8 SDK for several months at least.

Thank you very much for complete and accurate response.

Massimo Senatore

Firenze Web Division

Italy