1.VOLUP+VOLDOWN to boot into recovery
2.YAS537 Compass Sensor is not working
3.GPS not working properly
5.Camera but video recordings is possible
For updated bug report please follow XDA Thread from here.And you are ok with bugs and want to flash Cm13 rom Redmi 2 then you can follow below steps on How to Flash Cm13 rom in Xiaomi Redmi 2.Make sure you have custom recovery installed in your device. and make backup or current rom before flashing this.
#How To Flash CM13 Rom in Xiaomi Redmi 2.
2.Now paste both the file in your device memory and reboot your device in too recovery.
3.After rebooting to recovery flash CM13 rom from it and then flash Gapps6.0.zip.
4.Clear cache,Data and Factory reset your device
5.Now reboot your device done!
6.Enjoys Android marshmallow 6.0 in your Xiaomi Redmi 2.