Metropolis on the Ganges (5)
I believe the answer is:
patna
'metropolis on the ganges' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for patna that I've seen before include "Variety of long-grain rice" , "City of savoury rice" , "Long-grain rice type" , "Source of long-grain rice" , "Long-grained rice type" .)