Detective's record turning extreme agents in Republic, for one, leads to immunity (12)
I believe the answer is:
dispensation
'immunity' is the definition.
(thesaurus)
'detective's record turning extreme agents in republic for one leads to' is the wordplay.
I cannot really understand how this works, but
'detective's' could be 'dis' (Detective Inspector) and 'dis' is found in the answer.
'record' could be 'pen' (I've seen this before) and 'pen' is found within the answer.
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'to' is within the answer.
The remaining letters 'san' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dispensation that I've seen before include "Exemption (from usual requirement)" , "allotment" , "Permission to break a rule" , "Administration (of justice, etc)" , "immunity?" .)