To root use kingroot for WINDOWS COMPUTER (google to find) OR try this apk version (not tested)

https://sites.google.com/site/androidxdacom/file/KingRoot-4.1.0.524.apk

OR

Download update.zip from here

https://drive.google.com/folder/d/0Bxr0Y7ftq0hobm9qeWxHVjRVZDQ/edit

Put the update.zip in your sd card root folder and boot your phone to recovery mode. (Power off then press Volume down and power. Wait until it shows 3 mode select recovery mode with volume down then press volume up)
When in recovery mode choose apply update from sd card then press power button. When completed press power button again to reboot.

You are rooted. Next download “flashify” from playstore and install.

Now download TWRP Recovery from link below and put in your sd card.

https://drive.google.com/folder/d/0Bxr0Y7ftq0hobm9qeWxHVjRVZDQ/edit

Open flashify, give root permission, choose flash recovery, choose the downloaded twrp.img, after flashing done reboot.

Now go to this url and choose the iris708 rom you like and download. I tried all of them. Most of them buggy except emui 3.0 for irir708. Its perfect.

http://www.needrom.com/category/others/i-j-k-l/lava-other-categories/

After rom download put in your sd card then open flashify and choose “reboot into recovery” from top right menu.
The phone will boot in to recovery, choose wipe and swipe to wipe.
When completed hit back button on ur phone twice now choose install. Then choose the rom you have downloaded and swipe to install.
Reboot and enjoy.