Android 5 lollipop is not yet released for the Galaxy Note 10.1 2014 model but thanks to developers at XDA, we can taste it. This ROM works only for P605 but would not work on P600 and P601. Here are instructions on how to flash it.
Flash TWRP 188.8.131.52 using odin. Reboot into recovery. Go into wipe menu. Select "Advanced Wipe". Check Dalvik Cache, System, Cache and Data and wipe them. Don’t reboot just yet.
Now go into install and flash aosp-2015XXXX-lt03lte.zip, GAPPS.zip and then flash SuperSU.zip. Reboot now.