According to adilrenzu's guide
here we are now able to root Lenovo K6 Note successflully. This guide is for users who want to change their phones to the factory original state, downgrade from 7.0 or unroot. I tested this with my lenovo k6 note. Bu as you know rooting and unrooting operations are dangerous and may brick your phone. Please do it with your own risk.
This downgrade process supports full OTA Upgrade.
Reguired Files
First Download all required files from here
http://goo.gl/Gfs1zf
Install Drivers in 2_Driver.rar
Install softwares in 3_Microsoft C.rar (For 64bit Windows install Both)
Phone : In Developer Options >
>Turn on USB debugging
>Enable Oem Unlock
1. Uninstalling Root
We must uninstall root (supersu) on the device. Select supersu app and tap the settings.
Access > Default Access > Grant and Full Unroot > Continue > Yes > Yes
The phone is restarting now. Check the supersu app not in drawer.
Shutdown the phone.
2. Turn Phone To Download Mode.
Hold down together the Volume Up + Power button for a while. Release power key after lenovo logo shows up. On the menu select download. Download Mode dont have any screen. Screen is blank but working.)
Connect phone to PC
3. Flashing Rom
Unrar 5_K53_S123_170216_ROW_STOCK.rar (Latest) or 5_K53_S116_161115_ROW_STOCK.rar (Testing OTA)
Unrar 4_QcomDLoader.rar Open folder. Click and open QcomDloader.exe
On Downloder Window Click load button. (First on top left)
Select the directory of the rom files (The directory numbered 5 which contains many img files) Click OK.
Click settings button. (Second on top left)
Dont change anything. I was pre entered the options. Check the values. If wrong, correct.
Manifacture Order: EMPTY (Important)
Download Mode: UPGRADE
Chipset: 8937
Downloaded Rom: CHECKED
eMMC Programmer: prog_emmc_firehose_8937_ddr.mbn
Raw Program: rawprogram0.xml
patch0: patch0.xml
Click OK.
Click Start button. (Third on top left)
Status becomes Downloading. Wait for a while. Flashing finishes around 400-500 seconds.
Status becomes Finish. Progress Passed.
Disconnect the phone. Close the Downloader on PC.
Press Power button 10 seconds on phone. Device is restarting.
Wait a few minutes. Phone will be opened to first install mode . In language selection screen Shutdown the phone by pressing power button.
4. Installing ADB
Install 1_adb-setup-1.3.exe to the pc. (Select > Yes > Yes > Yes > Yes. In the opened window click Install)
5. Locking the Bootloader.
Restart phone in fastboot mode. (Hold down power + Volume DOWN keys. Fastboot Mode appairs left top of the screen.)
Connect phone to PC
Adb directory now located in C Drive. Open adb folder. Open a command window here. (CRTL+SHIFT right click on empty space. Select Open Command Prompt Here)
Type: fastboot devices then press enter. (Your device must be listing like: s356d3a9 fastboot)
Type: fastboot oem lock (OKAY [ 0.031s] finished. total time: 0.031s)
Type: fastboot oem device-info
Control all options are false.
Disconnect the phone. Restart phone by pressing power button 10 seconds.
Finished...
This rom contains no bloatware except Lenovo Help (a.k.a Lenovo Companion)
Changing The Phone Region (Optional)
Open Dialer > Type ####682# > Chose Your Region > Restart
Check Region > Type ####5993# > Last 2 chars are your region.
Changing the region gives you to access phone software's drive when connect it to PC
OFFICIAL ROM LINKS: (Lenovo Ota Server)
Update ROM S116-161115 to S123-170216
http://phonedl.ota.lenovomm.com/dls/v6/K53_S116_161115_ROW_TO_K53_S123_170216_ROW_WC2178D800.zip
Update ROM S123-170216 to S218-170605 (
Official Android 7.0)
http://phonedl.ota.lenovomm.com/dls/v6/K53_S123_170216_ROW_TO_K53_S218_170605_ROW_WC48DE0BA5.zip
Changelog
Added Lenovo Vibe K6 Note Android 7.0 Nougat Official Rom Link:
Download From Lenovo Server
Added Region Codes: S116-161115 Rom added to repository who wants to test OTA
....
: D 
