Commissar is in some Indian robe (4)
I believe the answer is:
sari
'indian robe' is the definition.
(I've seen this before)
'commissar is in some' is the wordplay.
'some' says the answer is hidden in the clue.
'SARI' is hidden in the letters of 'commissar is in'.
(Other definitions for sari that I've seen before include "Something worn" , "Hindu woman's dress" , "Traditional dress of Hindu women" , "Hindu female garment" , "Eastern garment" .)