Google had released the final version of Android 6.0 Marshmallow couple of months back and OEMs are busy developing the builds for their flagship devices. Recently OnePlus announced their third smartphone, the OnePlus X for Rs 16,999 in India and we also did the unboxing of the device. Today, OnePlus has announced via forum post on their plans to upgrade their devices to Android 6.0 Marshmallow.
Although the company has not announced any dates yet, the first device to get will be the current flagship phone OnePlus 2. Since OnePlus 2 runs on Oxygen OS from the company, it will be getting the update in Q1 2016.
For OnePlus users, Cyanogen will be releasing the Android 6.0 update in Q1 2016. Since the phone does not have Oxygen OS, company will also be updating the community build of OxygenOS for the OnePlus One, but only when time allows. The post also mentions that the company is working hard to bring Marshmallow as soon as possible to the OnePlus X, and the dates or time frame will be announced at a later time.
The company has also pushed kernel sources for the OnePlus X and available here.