I don't think the Reserve Bank has anything to do with coinage. They authorize printing and issue of banknotes, but coins are struck by the Mint on order direct from the Treasury. The Reserve Bank are more macro-economic policy guys and don't handle the fiddling small change.

Once upon a time the Reserve Bank branches all had a numismatic booth in them that sold crisp unc notes for face value to the public, but never coins.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis