The Android 6.0 Marshmallow upgrade has finally been set to release to Samsung Galaxy S6 models in January 2016. A new leaked photo revealed the news.

The Samsung Galaxy S6 units are expected to get the Android 6.0 Marshmallow update as 2016 opens next year, in line to the previously announced first quarter release of the upgrade. The leaked photo spoke of the status of the Galaxy S6 units, as approved for the Marshmallow upgrade.

The leaked material has a date "29 October 2015" on it while watermarked with 'TimesNews.co.uk'. It revealed two phases of the Android upgrade, while it was also stated that Phase 3 will commence after Initial Testing.

In previous reports, the upgrade has already been announced to the device confirming a total of 15 models to officially receive it. Currently, the upgrade is in the Initial Testing stage wherein the original equipment manufacturer went through preparatory tests of the new build whether or not it is suitable for the device. Last October, the device was in the Development stage where integration of the build had happened.

Here's a complete list of the Galaxy S6 devices in corresponding model number to receive the Marshmallow upgrade. They are all running on Android 5.1.1 Lollipop software version.

• SM - G920F
• SM - G920I
• SM - G9200 Duos
• SM - G920W8
• SM - G920P
• SM - G9208
• SM - G920R4
• SM - G9209 Duos
• SM - G920L
• SM - G920S
• SC - 05G (DoCoMo)
• SM - G920T
• SM - G920K
• SM - G920V
• SM - G890A (Active)

These models have already been approved to receive the upgrade, which means they are ready to take on the Marshmallow build per evaluation. However, despite the fact that they are up for a January 2016 slate, official release will vary depending on some factors, like location and carrier.

Being the biggest upgrade in Android's history, the Android 6.0 Marshmallow build will bring in a long list of new features and major tweaks in overall performance.