I don't know what currency will be used among the BRICS countries. But it is already a fact that:
- India paid gas in rupee to Russia - China paid oil in RMB to Saudi Arabia - Kenya wants to trade in the local currency with its neighbours instead of US dollar - Indonesia, Singapore, Malaysia, Thailand residents now pay goods and services using their own local currency (they don't need to buy US dollar anymore like before).
So it is obvious to me the de-dolarization process is unstoppable!
