The unit for accounting cash “exchange” is known as Guldens. Before the collapse of the VOC, a variety of coins were used in the east indies. They were Dutch coins, Spanish coins, and Asian coins. However, after the collapse of the voc, the currency became treasury notes with denominations of one, one and a half, and two and a half guldens.
The languages used were very varied. Since the main religion of the dutch east indies before colonization was Islam, the presumed language would be Arabic. Besides, there is proof that both Arabic and Dutch were used widely during the 1900s in dutch east indies as there are both Arabic inscriptions and dutch inscriptions on the coins produced during the era.
Dominant religion in the Dutch East Indies include Islam and Christianity. You can also notice followers from other religions such as Buddhism and Hinduism.