This refers to the version of the recovery. While older, it is often the most stable "full" version for legacy Tab E hardware.
If you run into a or Odin shows a "Fail" message, let me know: What version of Windows are you using? Is your tablet the Exynos or Spreadtrum version? Did you see a specific error code in Odin? twrp3021smt560tar full
Move from the aging TouchWiz interface to cleaner versions of Android (like LineageOS). This refers to the version of the recovery