Hello @irfan-relevantec,
When creating any of your transactions, the system will let you enter the amount with exactly 2 decimals only. But if it is the exchange rate of your currency, you can enter the amount for more than 3 decimal places.
Lastly, I've got you this helpful article for ideas about how you can utilize the multi-currency and its function: Multi-currency FAQ.
Stay safe and give us a comment if you have any other questions.
