immobiliser code for renault megane coupe?

I am looking for the immobiliser code for my renault megane coupe the chassis or vehicle identification number is VF1DA04B521624919. the immobiliser is on and the car wont start, central locking doesnt work so am going to change battery for key as suggested in a previous post this has happened once before but the central clocking was working then and i was able to get it working.