Old Indian copper is somebody with no need of rupees (4)
I believe the answer is:
peon
'old indian' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for peon that I've seen before include "Spanish-American farm worker" , "Day-labourer" , "lowly farm worker" , "A Mexican peasant or labourer" , "Spanish-American farm labourer" .)