The Galaxy Tab S2 9.7 originally ran on Android 5.0.2 Lollipop and one variant has already received an update to Android 5.1.1 Lollipop. If you have a Galaxy Tab S2 9.7 and you want to go beyond the boundaries Samsung place and access the true open source nature of Android, you are going to need to have root access and a custom recovery installed.
After enabling the OEM Unlocking and USB Debugging power off your device. Press and hold Volume Up + Volume Down and connect your phone to your PC. It will show a Warning screen on your phone, and now you can release both buttons. Now press the Volume Up button once, and Galaxy Tab S7+ will boot into Download mode.Open the Downloads folder and move both files over to the desktop. Right-click the files one at a time and choose the “extract here” option. Double-click the Odin executable file you get after extracting the Odin flashing tool file. Reboot the Samsung Galaxy Tab S2 into the download mode by holding the Volume Down + Home + Power button at
MMgD.