Take a backup of your data.In case something goes wrong.
Enable USB Debugging on your device.
Go to > Settings > Developer Options > USB Debugging.
If Developer Options is not located under settings then enable it by going to Settings > About Phone > Device Info and tap on Build Number for about 7-8 times. And then go back and follow previous step.
Make sure you have at least 50% battery.
Go to Settings > Security and enable Unknown Sources option.
Connect your Lenovo A6000 smartphone to your PC and install the application (CDROM) which you can see in your My Computer/This PC. ( This is important, I tried many other tutorials without installing this and my phone was not showing up. But after installing this, my phone was showing up on adb)
Setup ADB and Fastboot drivers on your PC from here.
Download the following Recovery.img and SuperSu Files for Lenovo A6000 from the below:
Step 1 : Extract the files which you downloaded. Step 2 : Copy the recovery.img file to C:Program Files (x86)Minimal ADB and Fastboot or C:Program FilesMinimal ADB and Fastboot directory. Step 3 : Open the C:Program Files (x86)Minimal ADB and Fastboot directory and press and hold shift key and right click anywhere inside the folder at the empty space and choose open command window here. Step 4 : Now in CMD type: adb devices
Step 5 : Now type adb reboot bootloader This will reboot your device into Bootloader / Fastboot Mode. Step 6: Now type fastboot boot recovery.img Once flashed type the following command to reboot Lenovo A6000. fastboot reboot Now you have successfully installed CWM on your Lenovo A6000 smartphone.