Nokia Mobile has rolled out a new Pie Build (V.3.54I) along with the August Security update for the Nokia 6.1. The update is 136.6 MB in size and brings under the hood improvements along with August 2019 Android Security patch. You can learn more about Android Security updates by visiting the Android Security Bulletin.
Nokia 6.1 users in India have started receiving the update and it should be rolling out to the other markets in the coming days. You can also manually check for the update to see if it is available for your Nokia 6.1 in your country.