The BRICs, as an anti-USA economic coalition are not living up their hype/ The pro-Putin crowd here has been hyping BRICs for years here.
As a political entity, the EU is dominated by a Franco-German political alliance that is secured militarily by NATO and the US. The EU central bureaucracy is characteristically thuggish and peremptory in its dealings with other members. That was enough to drive Britain out and limits the EU's appeal.
Nevertheless, the current EU members are close enough in interest, culture, and history to make it work. The euro has therefore become a mostly successful regional currency based on the strength of the German economy and Germany's willingness to subsidize and lend to other EU members.
The euro though never lived up to the hype that it would become a global currency alternative to the dollar. And the EU's joint arms programs have mostly failed, as has its effort to create an EU military as an alternative to NATO.
So, with those problems and limitations in the far more favorable context of Europe, just how can the disparate interests, culture, and history of the BRICs be merged into a successful political and economic alliance? To even pose the question illustrates just how improbable any success would be.
And with such shaky foundations for a BRICs alliance, just how can it be the basis for a viable currency? At most, a BRIC currency would become a way to settle a handful of deals between the BRIC members without using dollars. Even then, just how are excess credits to be more than dead book keeping entries instead of viable assets?
Gold backed credits could be used, but in the event, that would have to be a way of simply making BRIC member currencies convertible into gold between their central banks and national governments. And if that is what they intend to do, how can they prevent BRIC members from using their BRIC currency credits to poach gold from each other?
When France did that to the US, it helped push the US off the Bretton Woods system of limited gold backing for the dollar. Such an issue would easily explode the BRIC currency scheme because, unlike the dollar or the euro, it would not be founded on the underlying national economies.