How do I get coin supply on Bitcoin core? I've seen in other QT wallets I can get how many coins are in circulation typing a command like  getsupply, they also have this information in the output of the command getblock &lt;hash&gt;.
Is there a way to get this information using a RPC Command on Bitcoin Core?
It depends on what you want.
If you want to know the amount of currency that has been available for miners to bring into circulation (the &quot;210000-1 blocks of 50 BTC, then 210000 blocks of 25 BTC, then 210000 blocks of 12.5 BTC, ...&quot; rule), the answer is no, there is no RPC that computes this. It's easy to do yourself, though.
If you want to compute the amount in circulation, namely the sum of all UTXO values, there is; it is computed by the gettxoutsetinfo command.