Which iOS for iPhone 6s and 6s Plus?

[slojave]

I'm assuming the iPhone 6s and 6s Plus will come with iOS 9.

If I'm running iOS 9.0.1 and do a back-up can I restore on my iPhone 6s Plus which is running iOS 9?

Any thought would be much appreciated!

 

[Cayden]

I'm assuming the iPhone 6s and 6s Plus will come with iOS 9.

If I'm running iOS 9.0.1 and do a back-up can I restore on my iPhone 6s Plus which is running iOS 9?

Any thought would be much appreciated!

It will most likely update when you plug it into the computer and then restore from the 9.0.1 back up. iPhones generally can't restore from newer versions of iOS