Note: Flashing firmware can be risky and might lead to data loss or even bricking your device if not done correctly. Make sure to follow the steps carefully and back up your important data before proceeding.

Before you begin:

1. Backup: Make sure to backup all your important data as flashing firmware will erase everything on your device.

2. Charge: Ensure your phone has sufficient battery charge (at least 50%) to prevent any interruption during the flashing process.

3. Download Firmware and Tools: Download the correct firmware for your Xiaomi Redmi 6 and the latest version of SP Flash Tool on your computer.

4. USB Drivers: Install the Xiaomi USB drivers on your computer so that your device can communicate with the SP Flash Tool.

Flashing Steps:

1. Extract Firmware: Extract the downloaded firmware package on your computer to a folder.

2. Install SP Flash Tool: Install the SP Flash Tool on your computer if you haven’t already.

3. Open SP Flash Tool: Launch the SP Flash Tool on your computer.

4. Load Scatter File: In SP Flash Tool, click on “Choose” or “Scatter-loading”, then navigate to the firmware folder and select the scatter file. The scatter file is a text file with the extension “.txt” that tells the SP Flash Tool how to flash each partition of the firmware.

5. Select Flash Options: In the SP Flash Tool window, you’ll see various options for flashing different parts of the firmware. These might include “Download Only,” “Firmware Upgrade,” and more. Select the appropriate option based on your needs. Generally, “Firmware Upgrade” is used to update the firmware.

6. Connect Phone: Turn off your Xiaomi Redmi 6. Press and hold the volume down button, then connect the device to your computer using a USB cable. This should put the device into “Download” or “Flashing” mode.

7. Start Flashing: Once your device is connected and recognized by SP Flash Tool, click the “Download” or “Firmware Upgrade” button in the tool. The flashing process will begin.

8. Flashing Progress: The tool will start flashing the firmware. You will see a progress bar indicating the flashing process. Do not disconnect your device during this process.

9. Flashing Complete: Once the flashing process is complete, you’ll see a “Download OK” or “Finish” message in SP Flash Tool.

10. Disconnect and Reboot: Disconnect your device from the computer. Your Xiaomi Redmi 6 might not boot up immediately; it might take a bit longer than usual during the first boot. This is normal.

Remember that these instructions are based on general steps for flashing MTK-based devices. The exact steps might vary slightly based on the specific firmware and version of SP Flash Tool you’re using. So we can’t take responsibility for these instructions. Always refer to the official documentation and resources for your device and tools.