These are the instructions to root Motorola Moto G (2015) using the TWRP recovery on Windows Computer.
Requirements: Your smartphone should have atleast 20-30 percent of battery to perform the rooting process.
Step 1: Follow the step-by-step instructions to unlock bootloader on your Motorola Device.
Step 2: Once you have successfully unlocked the bootloader on Motorola Moto G (2015), then you need to install custom recovery (i.e TWRP or CWM recovery). For that you have to connect your device to the computer first then follow the below steps.
Step 3: Download SuperSU (latest) and move it to the root of the Phone SD memory.
Step 4: Download and install the Minimal ADB and fastboot Tools on your computer.
Step 5: Download TWRP recovery (v2.8.7 tested working) on your computer and rename it to recovery.img.
Step 6: Now, move the TWRP recovery file to the Minimal ADB and Fastboot folder (i.e C:Program FilesMinimal ADB and Fastboot).
Step 7: Now, Open MAF32.exe or py_cmd.exe from the Minimal ADB and Fastboot folder.
Step 8: Give the Following Command: adb devices
The above command helps to know the list of attached devices to the computer.
Step 9: Now, Give another command: adb reboot bootloader
The above command helps you to boot into the adb mode.
Step 10: Now, give another command: fastboot flash recovery recovery.img
Step 11: Now, TWRP recovery will be installed on your phone and you will be able to see some process on your Device screen.
Step 12: Now, you need to boot into the ADB mode. To boot into adb mode, Press and hold the Volume Down Key and Power Key (for 4-5 seconds) and release the power key but keep holding the Volume Down key until ADB mode is visible on the screen.
Step 13: Once you have booted into the ADB mode, Select Recovery (use volume down for scrolling and Volume Up to select).
Step 14: Once you have booted into the TWRP recovery mode, Tap on the Install and select the SuperSU package that you have moved to the Phone SD in Step#3.
Step 15: Now, reboot your Device from the TWRP recovery.
Step 16: Once your Device is restarted you will be able to see the SuperSU icon in the Menu. Which confirms that you have successfully rooted your Motorola Moto G (2015).
Optional: You can also verify the root status of your device by using the Root Checker Application.
[*] No data loss process: Your Personal Data including contacts, pictures, videos, music wont be affected using the above method. In short, no data loss process.
[*] How to remove Unlocked Bootloader Message: If you have unlocked the bootloader on Motorola Moto G (2015), then you might be getting Unlocked Bootloader message when you restart your device. You can disable or remove this message by following how to remove unlocked bootloader message on Moto G (2015).
[*] Motorola USB Driver: If you are looking for the original USB Driver for your device then head over to Download Motorola USB Driver for all devices page.
[*] Big thanks to Chainfire for their SuperSU file for Motorola Moto G (2015), without this tool the above tutorial was not possible.