Kingoroot, Kingroot and other programs don't work but follow these steps:
1. U need to download:
1.2. TWRP recovery
1.3. SP Flash Tool
1.4. scater (here is and cwm recovery if someone doesn't like TWRP)
2. When you download this copy super-su in your sd card and turn off your phone.
Open sp flash tool and click on scatter-loading and chose "MT6580_Android_scatter" in scater + recovery folder if u want cwm recovery or in TWRP 3.0 folder if u want TWRP recovery and click download.
Connect your phone with USB and press power button and volume + button in same time, your phone will boot recovery which you chosen. Find super-SU which you copied on sd card and flash it.
Reboot and that is it your phone is rooted.