Calcutta cash (6)
I believe the answer is:
rupees
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">calcutta cash</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rupees that I've seen before include "Indian monetary units" , "Coins of India" .)