The Nokia 6 (2018) comes with Android 7.1 Nougat pre-installed. However, HMD promised to quickly push out the Oreo update to the device. Well, the good news is that has already started happening.
Latest reports say Nokia 6 (2018) units are getting Android 8.0 on very first boot.
Reports also confirm that the device comes with optional support for Google services in China. This means those in the Asian country will be able to install the Google Play Store on their units.
It's worth mentioning that once installed, you'll not be able to un-install the Play Store apk.