We got reports that Android Oreo is now seeding to the HTC 10 smartphones in India. It should be available as an OTA update to all supported units soon, if not already. The update brings support for Jio VoLTE in addition to the new version of the Google's OS. The Oreo update for the HTC 10, just like it happened to other popular devices, was off to a rocky start as HTC quickly pulled the first batch of the ROMs. It was resumed later on. For comparison, Sprint units in the US have had access to the Oreo update since February 12. Thank you, Hrishikesh, for the tip!
Source: https://www.gsmarena.com/htc_10_is_now_getting_android_oreo_update_in_india-news-29840.php