If you are not sure which version you have, do not flash anything yet. Go to FreakTab.com, search for "Tanix TX3 Mini," and read the sticky posts. They usually provide a spreadsheet matching Serial Numbers/Motherboard versions to the correct firmware file.
Here are several interesting text options about "tanix tx3 mini firmware" you can use—pick one or mix them: tanix tx3 mini firmware
Required:
For Android ZIP updates:
To avoid bricking, perform this before flashing: If you are not sure which version you
TX3_MINI_V1.2).