Any idea whether it's silver or some base metal? The side with the temples almost certainly pins it as thailand, sometime before 1900. What puzzles me is the arabic writing on the reverse--much more typical of say Indonesia.
If it is silver, I'm inclined to say maybe an unofficial trade currency? Indonesia has been struggling for years to combat privately minted gold and silver coins by hardline conservative Muslims who only honor the denominations laid out in the Quran. Thailand mostly jumped straight from crude stamped ingots to modern minting technology, so the sharp details does not match up with the poor centering and undersized flan.