Awesome! I have a bit of a collection of these Palembang pitis, they're a lot of fun. It looks like yours is a clump of two pieces combined after being buried in the mud of the Musi River. The date reads 1203 AH so it's 1788-1789 CE. Southern Sumatra -> Central Sumatra Jambi Sultanate Sumatra
Johor Sultanate Present-day Malaysia Undated (1528 - 1800s) Tin Katun - Octagonal Planchet Obv: "Malik" meaning "King or Ruler" Rev: Appears blank Ref: SS36
1730 Holland VOC duit. I think all or most of present day Indonesia was controlled by the Dutch East India Company during the 1700s.