City Hall finally took part in Green Revolution (6)
I believe the answer is:
dallas
'city' is the definition.
(Dallas is an example)
'hall finally took part in green revolution' is the wordplay.
I cannot quite understand how this works, but
'part' could be 'la' (la is a kind of part) and 'la' is present in the answer.
The remaining letters 'dals' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dallas that I've seen before include "Texas city where JFK was assassinated" , "former TV series" , "city built on oil" , "US city where JFK was assassinated" , "City in Texas; TV series" .)