Vehicle making a comeback in Nagasaki or Tokyo (6)
I believe the answer is:
troika
'vehicle' is the definition.
(troika is a kind of vehicle)
'a comeback in nagasaki or tokyo' is the wordplay.
'a comeback' is a reversal indicator.
'in' indicates the answer is hidden within the clue.
'akiort' is hidden within 'nagasaki or tokyo'.
'akiort' reversed gives 'TROIKA'.
'making' acts as a link.
(Other definitions for troika that I've seen before include "Threesome" , "Russian vehicle drawn by three horses abreast" , "Russian horse-drawn vehicle" , "Three-horse Russian vehicle" , "Russian three-horse carriage" .)