Grand won by tyrant after card game somewhere in Balkans (10)
I believe the answer is:
montenegro
'somewhere in balkans' is the definition.
'grand won by tyrant after card game' is the wordplay.
'grand' becomes 'g' (G is short for grand as in a thousand).
'won by' is an insertion indicator.
'tyrant' becomes 'nero' (Nero was a tyrant).
'after' is a charade indicator (letters next to each other).
'card game' becomes 'monte' (monte is a kind of card game).
'g' placed inside 'nero' is 'negro'.
'negro' put after 'monte' is 'MONTENEGRO'.
(Other definitions for montenegro that I've seen before include "European country (bordering on 6)" , "Balkan state" , "Balkan republic" .)