Let's call the BRIC-based currency a "Brick" . One measure of "success" would be use as a reserve currency in a significant percentage of global trade.

A second measure of "success" involves sanction avoidance. The second measure is far more likely to succeed for many reasons. Let's start with the first measure of success.

What Would it Take for the "Brick" to Succeed?

The Brick would need to float freely. The yuan doesn't.

The Brick have to be a genuine reserve currency to achieve widespread use.

A functioning Brick-based bond market. This requirement is also for widespread use.

A significant desire by individuals to trade in Bricks and accept Bricks rather than local currencies or the dollar.

Willingness of China to stop export mercantilism.

Trust