Robber bands round eastern river (6)
I believe the answer is:
ganges
'river' is the definition.
(Ganges is an example)
'robber bands round eastern' is the wordplay.
I cannot quite understand how this works, but
'eastern' could be 'e' and 'e' is found within the answer.
'bands' could be 'gangs' (I've seen this before) and 'gangs' is found in the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ganges that I've seen before include "River flowing into the Bay of Bengal" , "Sacred river of N India" , "Sacred Hindu river in India" , "Holy water" , "Great river of India" .)