Container raised in low principality (6)
I believe the answer is:
monaco
'principality' is the definition.
(I know that Monaco is a principality)
'container raised in low' is the wordplay.
'container' becomes 'can' (can is a kind of container).
'raised' is a reversal indicator (going up in a down clue).
'in' is an insertion indicator.
'low' becomes 'moo' (both can mean to make the noise of a cow).
'can' reversed gives 'nac'.
'nac' placed into 'moo' is 'MONACO'.
(Other definitions for monaco that I've seen before include "Mediterranean principality" , "Southwest European principality" , "Med principality" , "Monte Carlo country" , "Principality of the Rainiers" .)