Placing financial restriction on ordinary folk is old hat (6)
I believe the answer is:
mobcap
'old hat' is the definition.
(I've seen this before)
'placing financial restriction on ordinary' is the wordplay.
'placing' becomes 'mb' (I can't explain this - if you can you should give a lot more credence to this answer).
'financial restriction' becomes 'cap' (eg a cap on expenses).
'on' is an insertion indicator (as in clothing 'on' a person).
'ordinary' becomes 'O' (abbreviation e.g. O-Levels).
'mb'+'cap'='mbcap'
'mbcap' placed around 'o' is 'MOBCAP'.
'folk is' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
(Other definitions for mobcap that I've seen before include "old hat" , "headgear" , "Old-fashioned womans hat" , "18th-century woman's indoor hat" , "C 18 - nineteen women's large soft indoor hat" .)