Samsung Galaxy Note 4 is the best phablet on the market, at the least going by the hardware it packages.

Rooting Galaxy Note 4 allow you to develop privileged or even admin accessibility to the Android sub-system. The root for the Galaxy Note 4 had been realized by popular XDA contributor, Chainfire, who’s got expert fantastic experience rooting unreleased devices previously.  Right now, Chainfire’s CF-Root will be the best way to rooting Galaxy Note 4.

Pre-Install Requisites

• Install USB Drivers for Samsung Galaxy Note 4 to connect the Android device with the computer.
• Enable USB Debugging Mode on phone to connect it with the computer and use Android SDK with it. [Navigate to Settings>> About phone>> tap Build number seven times. A pop up will appear, that reads, ‘You are now a developer.’ Go back to the Developer options and check USB debugging and click OK.]
• As the tutorial is likely to wipe out all data of the phone, create a backup. If the device is having any custom recoveries such as CWM/TWRP then backup data using the same.
• If the Android phone powers off due to lack of battery while the installation process, it could damage the device. Therefore, the Note 4 should have charge above 80% battery charge.
• Rooting the device will void the device of manufacturer’s warranty.

Verify model number of the device and install root package accordingly. Flashing incorrect file might brick the device.

Step by Step how to root Samsung Galaxy Note 4 using CF-Auto-Root

1. Download CF-Auto-Root package for galaxy Note 4, according to the model number
   Download List
   SM-N910F (International, Qualcomm): CF-Auto-Root-trlte-trltexx-smn910f.zip
   SM-N910G (Asia, Qualcomm): CF-Auto-Root-trlte-trltedt-smn910g.zip
   SM-N910H (Asia, Exynos): CF-Auto-Root-tre3g-tre3gxx-smn910h.zip
   SM-N910T (T-Mobile USA, Qualcomm): CF-Auto-Root-trltetmo-trltetmo-smn910t.zip
   SM-N910P (Sprint, Qualcomm): CF-Auto-Root-trltespr-trltespr-smn910p.zip
   SM-N910R4 (US Cellular, Qualcomm): CF-Auto-Root-trlteusc-trlteusc-smn910r4.zip
   SM-N910W8 (Canadia, Qualcomm): CF-Auto-Root-trltecan-trltecan-smn910w8.zip
   SM-N910C (Thailand, Exynos): CF-Auto-Root-trelte-treltexx-smn910c.zip
   SM-N910U (Hong Kong, Exynos): CF-Auto-Root-trhplte-trhpltexx-smn910u.zip
   SM-N910K (Korea, Exynos): CF-Auto-Root-treltektt-treltektt-smn910k.zip
   SM-N910L (Korea, Exynos): CF-Auto-Root-treltelgt-treltelgt-smn910l.zip
   SM-N910S (Korea, Exynos): CF-Auto-Root-trelteskt-trelteskt-smn910s.zip
   SM-N9100 (China, Qualcomm): CF-Auto-Root-trltechn-trlteduoszc-smn9100.zip
   SM-N9106W (China, Qualcomm): CF-Auto-Root-trltechn-trlteduoszn-smn9106w.zip
   SM-N9108V (China, Qualcomm): CF-Auto-Root-trltechn-trltezm-smn9108v.zip
   SM-N9109W (China, Qualcomm): CF-Auto-Root-trltechn-trlteduosctc-smn9109w.zip
   Other models
   CF-Auto-Root is not yet available for all models – one stock firmwares for these models become available, let me know, and I’ll make the corresponding CF-Auto-Roots. Make sure to check the main CF-Auto-Root site as well, as models may be listed there that are not listed here yet!
2. Extract the downloaded zip to your computer If you get a recovery.img and cache.img file, you have extracted twice. You should get an Odin flashable file with .tar.md5 extension
3. Download Odin v3.09 [here] and extract the zip
4. Power off the Galaxy Note 4
5. Put the phone in download mode. To do so hold Volume Down, Home and Power buttons together. Press a button from the listed menu when it ask to do so to continue the process
6. Connect the phone to the computer using USB cable while it is in the download mode. Wait for some time until Odin detects the device. When the phone is connected successfully, the ID: COM box in Odin will turn light blue with COM port number. This step might take some time
7. In Odin, click AP button and select the firmware file with .tar.md5 extension
8. Ensure Re-Partition checkbox is not ticked
9. Verify everything and click the Start button in Odin

Wait for some time until the installation process is completed then boot the phone.

Note:
Many times the Android device doesn’t boot into recovery mode and root the device. If this occurs, then redo the entire process.

When it is still not rooted, make sure that Auto Reboot option in Odin will not be checked. Once flashing the root package, remove the battery and even boot the device into recovery mode just by holding the Volume Up, Home and Power buttons together. Doing this will begin the installation process. Your Galaxy Note 4 will ideally be rooted successfully.

Source: XDA Developer Forum