Highwayman Bar is for returning heads, teachers, instructors, disciplinarians? (6)
I believe the answer is:
bandit
'highwayman' is the definition.
(I've seen this in another clue)
'bar is for returning heads teachers instructors disciplinarians?' is the wordplay.
'bar' becomes 'ban' (I've seen this in another clue).
'is for' is a charade indicator (letters next to each other).
'returning' says the letters should be written in reverse.
'heads' indicates taking the first letters.
The first letters of 'teachers instructors disciplinarians' is 'tid'.
'tid' in reverse letter order is 'dit'.
'ban'+'dit'='BANDIT'
(Other definitions for bandit that I've seen before include "Highwayman" , "Criminal type" , "Armed outlaw" , "Marauder" , "Violent outlaw" .)