The most common and most likely answer to this crossword clue is the 6 letter word COPERS
I've seen this crossword clue in The Guardian
C
O
P
E
R
S
More clues leading to the result COPERS
Buddy explains!
The straight part
We know that "They manage the main booze suppliers /They manage/the main booze suppliers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they manage the main booze suppliers /they manage/the main booze suppliers = copers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COPERS mean?
COPERS noun- One who copes.
- A floating grog shop supplying the North Sea fishing industry.