I agree with Ivayla - if you're in America, you'll be hearing it as a Latin American Spanish name so gra-SEE-a, like the word 'gracias'. In Italian it's 'grazi' and you do hear a bit of a hidden t in there - grat-ZEE and the name is Grazia - gra-tZEE-a.
Castillian I give wide berth ;o)
Devon