law: Coinage Act, 2011
  Chapter III Coinage
  4. Denominations,
  
  dimensions, designs and composition of coins.-
  Coins may be minted
  
  at the Mints or at any other place authorised under the proviso to section 3 of
  
  such denominations not higher than one thousand rupees and of such dimensions
  
  and designs and containing such metals or mixed metals of such composition or
  
  any other material as may be prescribed by the Government.