leave and lease agreement

in the leave and lease agreement of the flat where i was leaving earlier there was a lock in period of 8 month(agreement was for 11 month). i resided there for 6months. my owner deducted 2 months rent from deposit stating that there was lock in period. despite of no loss as the flat is already occupied by another tenant can he deduct the deposit. plz suggest if there is any way to get my money back.