Alternative Android OS developer Cyanogen has released the Marshmallow-based CyanogenMod 13 nightly builds for a number of new devices. The list includes the OnePlus 2, Yu Yureka, Moto X Pure, Oppo R5 and R5s, and the Xperia Tablet Z.
The nightlies bring Android version 6.0 to these devices. Keep in mind that the builds may contain bugs as they usually aren't stable. Plus, installing them may not only result in a bricked device, but also void your handset's warranty.
In case you missed, the OnePlus 2 has already started receiving the official Marshmallow update.