Work for policemen including time in station (5)
I believe the answer is:
caste
'station' is the definition.
(as in social station)
'work for policemen including time' is the wordplay.
'work for policemen' becomes 'case' (as in detectives working on a case).
'including' indicates putting letters inside.
'time' becomes 't'.
'case' going around 't' is 'CASTE'.
'in' acts as a link.
(Other definitions for caste that I've seen before include "Level in society" , "Hereditary class (in India)" , "Social class in India" , "Religious or social class" , "Persons with class" .)