HTC has begun seeding the Android 4.4 KitKat update for the One Max, One Mini and One Dual-SIM. According to the Taiwanese phone maker, the rollout of the update began earlier today. As always, do not fret if you haven't received an update notification yet (check in 'About', inside 'Settings'), the process takes days (sometimes weeks) to reach every device. An official changelog hasn't been provided as of yet.
UPDATE: HTC India has confirmed that the update is now seeding, via a tweet from their official Twitter account.