Android N Developer Preview for Xperia Z3 was released earlier today and this was very quick from Sony and Google to land Android N Developer Preview out of Nexus line. Google has already released Android N Developer Preview 2 (DP2) for Nexus range.
For the time being Android N Developer Preview is released for Xperia Z3 D6603 and D6653 variants only and can be flashed on devices using Flashtool.
Android N Developer Preview for Xperia Z3
It is a good step from Sony giving developers a chance to test their apps on developer preview of Android N which will be later released by Google as a stable version.
[UPDATE] How to install Android N Developer Preview NPC91K on Xperia Z3, Tutorial here!Android N brings features likes multi-window, bundled notifications, direct reply notifications, increased efficiency.
Follow the source link if you are looking to flash Android N Developer Preview on your Xperia Z3.
Source – Sony Mobile