I want to know that if I want to add photon view in the object does that target object must be a prefabs?
It’s possible, yes. You can add a PhotonView, assign a viewID and a list of observed components. You need to make to make sure late joining players get this (e.g. from the cache on the server) and you need to clean up the server’s cache (if that’s used).
We call it Manual Instantiation.