You are caught punching young man in office (6)
I believe the answer is:
bureau
'office' is the definition.
('bureau' can be a synonym of 'office')
'you are caught punching young man' is the wordplay.
'you' becomes 'u' (I've seen this in other clues).
'are caught' becomes 'r' (I can't justify this - if you can you should give a lot more credence to this answer).
'punching' means one lot of letters goes inside another (I've seen this in other clues).
'young man' becomes 'beau' ('beau' can be a synonym of 'young man').
'u'+'r'='ur'
'ur' placed inside 'beau' is 'BUREAU'.
'in' acts as a link.
(Other definitions for bureau that I've seen before include "Agency - writing desk" , "The ------, familiar name of the FBI" , "French office - desk" , "Piece of furniture with drawers" , "Government department, agency" .)