Groups playing a set on court, with love (6)
I believe the answer is:
octets
'groups' is the definition.
The answer is an example.
'playing a set on court with love' is the wordplay.
'playing' is an anagram indicator.
'on' means one lot of letters go next to another.
'court' becomes 'ct' (abbreviation used in road names).
'with' is a charade indicator (letters next to each other).
'love' becomes 'o' (love means zero in tennis).
'set' is an anagram of 'ets'.
'ct' after 'o' is 'oct'.
'ets' after 'oct' is 'OCTETS'.
(Other definitions for octets that I've seen before include "Sets of eight" , "Groups of eight, often singers" , "Groups of eight peformers" , "groups of eight, say singers" .)