HTC has been on a roll pushing out Android Marshmallow update to their devices including devices in the Desire series too. Last we reported about HTC Desire 820 receiving it in China and Europe and now it is turn of Desire 820 users in India to receive it.
The update is around 925MB in size. So it is highly recommended to be on a strong Wi-Fi connection to avoid any interruption. The ROM version moves up to 3.17.1400.4 . The updates is also expected to be coming soon to other variants of HTC Desire 820. The update comes in phases. So you need to be patient in order to receive it on your device if you are in other markets.
Android 6.0 Marshmallow brings many new features like Google Now On Tap, App permissions, smart battery Optimization doze and many more. You can read our Big master list for Android Marshmallow roll-out for all devices from all vendors.