How to install ROM in Android Mobile Phones Tips By: ViDiKHAN
We are going to make our old os into new First of all you need android phone

TWRP  Recovery – Download it from here
Lenovo A6000 CM 13 Marshmallow ROM – Download it from here
GApps 6.0 – Download it from here

Install ADB drivers in your PC
Install Mobile drivers
Connect mobile via cable and turn on usb debugging
Now go to program files folder and find adb installed folder and click on py_cmd.exe
A command prompt window will appear on screen
Type these commands
adb devices
adb reboot bootloader
fastboot boot imagename.img
Program will load the boot image to mobile and mobile application will appear
Now allow modifications to slide the menu
Click on install button to find
Slide to install and wait for completing
After completing the process click on install button and click and press installation.

All done. Reboot your phone and enjoy.. .!
( First boot will take some time to prepare )
Thanks if you experiencing problems than contact me