When HTC unveiled the One A9 in October 2015, it promised that it would bring the latest Android updates to the handset within 15 days of their release to Google's Nexus devices. HTC later abandoned that commitment, and even after Google had released its Android 7.0 Nougat update in August 2016, it provided no clear indication of when it would bring that new version of the OS to the One A9.
HTC finally began its Nougat rollout for unlocked models of the device in January, expanding its availability to Europe last month. Now, eight months after Google released Android 7.0, the update is finally making its way to the HTC One A9 in India.
The update bumps the handset's software version up to 2.18.707.1, and is around 1.05GB in size. In addition to the various improvements that Nougat brings, the update also promises the "latest Android security update". It's not yet clear if that actually refers to the most recent April security update that Google released a couple of weeks ago - but that seems unlikely, given that HTC pushed the February patches to the One A9 in Europe at the end of March.
Source: The Android Soul