The update has been rolled out in Europe just a few days ago. Today, it comes in India as well, for both of the devices.
Shortly about the newest Android version, it comes with many new features that may increase the performance on your device. From the features, it includes the Grace UX that is a new gesture-friendly camera interface. Also, there is a redesigned status bar with stackable notifications, and a new Pop-up View mode.
If you want to check manually if your device is ready to receive the Android 7.0 Nougat, you can click on Check for Updates menu. It is mostly recommended that you use Wi-Fi for downloading the update, to avoid any potential charges on your device.