Official revision of rota in New York (6)
I believe the answer is:
notary
'official' is the definition.
(I know that notary is a type of official)
'revision of rota in new york' is the wordplay.
'revision of' indicates anagramming the letters.
'in' is an insertion indicator.
'new york' becomes 'ny'.
'rota' anagrammed gives 'otar'.
'otar' put within 'ny' is 'NOTARY'.
(Other definitions for notary that I've seen before include "A public one certifies documents" , "Official authorised to witness document signing" , "legal worker" , "Public records official" , "One authorised to perform certain legal functions" .)