Instantiate Object with Parameters (In Same Line)

Is it possible to send a message to a prefab that im instantiating in the same line? I am using unity networking so I have to have unity send it in the same line so it doesnt send the message to the rest of the players.

No, it is just casting UnityEngine.Object into GameObject, but if you want to call a method on a specific script on that GameObject, you can do :

(Instantiate(prefab) as GameObect).GetComponent<myScript>().myMethod();