Temasek's CM 13 for MT6582 is an aftermarket ROM based on Android M/CM13, This ROM has top of the line optimizations and awesome performance, One of the smoothest ROM I have compiled and used, not only does it come with performance, it comes with loads of awesome customization's and features. This ROM was compiled by Ajit Guraya and ported by Admin2.

Notes :
1) My only request is that do not at any cost forget to give proper credits. All credits are mentioned below
2) It only takes a few minutes to steal the ROM but it will take you months to request the developers to start working on development again. Many devs stopped working and sharing their codes just because of kanging and I do not want that to happen again.
3) CM 13 could have become more stable till now if it weren't for kangers who forced the devs to stop their work.

Credits :
Ferhung - The man behind CM13 for MT6582
Fire855 - Another legend
Hyperion70, Admin2
www.mtkroms.com
Ajit Guraya - Compiled Temasek's CM13 for MT6582 from source and fixed camera !
Minh Quoc and Karim Gahgah - For video recording fix
Aniruddha Adhikary - For his amazing USSD Fix
Sergey Kochetkoff - For his amazing GPS fix
Team Roger That - Ajit Guraya, Diparth Shah, Pawan Diyal, Ashutosh Dubey, Waseem Maya, Ankit Bhatangar, Rohan Taneja, Vipul Jha, Pranav Reddy 
Temasek, Arter97 – For developing Temasek
Required blobs (Really huge thanks) :
nofearnohappy, Varun Chitre, Ariafan, Vald.masti, Fire855, Alex

What's Working :
Camera
GPS
Video recording in stock/snap camera is working with 1080P !
Audio in calls
Bluetooth
USSD
Audio
Mic
RIL
SMS (Receive and Send both working)
WiFi
Data
RIL is now more stable
Dual SIM
Gapps
Hotspot
Screen Recording
Both storages (SD and Internal) mounting in both Phone and PC
Gapps
720P working in youtube

Bugs : orientation ; /

any rom (AOSP,AOKP,CM) who claims that their rom is bugless , is reluctant to speak about orientation bug, cause none have the fix, it's just 6.0.1 code for sensors doesn't support m2 hardware till now, may be in future releases this problem will be fixed, I HAVE TRIED ALL ROMS (6.0.1) DEVELOPED FOR GIONEE M2, WORKED WITH THEM , BUT THE BUG IS PERSISTANT.

AND ANOTHER THING BEFORE TRYING MARSHMALLOW DO A GOOGLE SEARCH FOR MARSHMALLOW PROS AND CONS..

Use these steps for flashing:—

1.make sure you’re phone’s rooted. https://play.google.com/store/apps/details?id=com.hexamob.howtoroot&hl=en

2.backup recovery &kernel https://play.google.com/store/apps/details?id=com.cgollner.flashify

3.flash twrp recovery for gionee m2 http://forum.xda-developers.com/gionee-m2/general/custom-twrp-2-8-5-touch-recovery-gionee-t3150785

4. take a nandroid backup via TWRP

5.wipe data &cache first (this is a must)

6.flash the downloaded zip file. (( tip: make a folder named 1a in sd card, keep the zip file in there in order to access it quickly while flashing))

7.wait 3-5 mins. if more than 6 minute then it’s bootloop or soft brick switch the phone off remove battery wait 5 minutes, start phone by volume up +power button(enter recovery)
wipe cache &data try flashing again.
or restore backup

8.Flash GAPPS directly after flashing the ROM

- Reboot

- After booting, Reboot your device to Recovery Mode

- Flash SuperSU

- Reboot