IPC Section 230

Coin — Coin is metal used for the time being as money, and stamped and issued by the authority of some State or Sovereign Power in order to be so used.

Indian coin — Indian coin is metal stamped and issued by the authority of the Government of India in order to be used as money;

And metal which has been so stamped and issued shall continue to be Indian coin for the purposes of this Chapter, notwithstanding that it may have ceased to be used as money.