Couple of days back YU has announced that they will be slowly rolling out Android Lollipop based CyanogenMod 12 update for all YUREKA users and all users will get notified once update reach their respective devices, or you can also manually check whether update is available for your device or not by simply going to Settings -> About -> System Updates, but as per news this update is rolling out very slowly and there are very less chances that update is available for you.
If you want to apply update right away then you can do this by following a simple process mention below. Keep in mind that as file which we are going to flash for update is the official file and thus it will not void your warranty, but as flashing ROM requires extra attention and care so if you are not familiar with this process, should not go ahead, if anything goes wrong with you or your device then only you and only you will be responsible for it.
Back up everything, flashing official ROM wont let you lose your data but we recommend you to back data
Some free time
Once you had downloaded the official ROM from above link, transfer it to your internal SD card, and then head toward Settings -> About and tap on your build number seven times to enable Developers Options, once its enabled head over to it and check Advance Reboot option.
Now press and hold the power button and tap on Reboot and then tap on Recovery, it will reboot your device into recovery mode. Once you are into recovery mode, use your volume buttons to navigate and power button to select. Into recovery mode go to Wipe Cache Partition.
Once its done select Apply Update -> Choose Update From Internal Storage -> 0/, and select your downloaded file to flash, it will take some time to complete, select Reboot System Now and it will take some time to reboot, say 15 minutes, so dont panic.
Once its done, you will have all new Android Lollipop based CM12 on your YU Yureka, do leave your comments below to let us know your feedback on it.