Huawei Mediapad M2 8.0 M2-801L Russian variant has been upgraded to marshmallow,  according to the official changelog following are features of this update

Update features

This update changes the current system version to EMUI 4.0 to adapt to Android 6.0. Compared to earlier versions, Android 6.0 has improved security, stability, and management performance. EMUI 4.0 has improved the UI and settings based on earlier versions.

Multiple view modes

• Provided small, medium, and large view modes

Call

• Added the auto-redialing feature

Home screen

• Optimized the recent task management, which now displays recent tasks in card form
• Optimized the settings screen in a Simple home screen style

System

• Optimized the system, which ensures smooth device operation
• Optimized the storage solution, which improves device responsiveness
• Provided more secure rights management
• Optimized the power-consumption firewall, which monitors background apps and detects power-intensive apps.

• Download Link: M2-801LC170B202
• File Size: 1.51 GB
• Firmware Type: Full Firmware OTA
• Supported Models: M2-801LC170 (Russia)

Installation Guide

• Backup important data
• Battery should be at least 40% charged
• 4 GB free space
• Make a dload folder on the internal / SD card
• Extract the downloaded file and copy the UPDATE.APP file to dload folder.
• Switch off your tablet then press and hold (volume up, volume down, and power) until you see the update start screen.