Network variable

I am learning Netcode concepts and I have a question about network variables.
When i chanche a value of a network variable in the server, this change is propagated on all client.
I know that there is a callback settable when the value is changed. Can I use this callback to know that all client received the synchronization? I need to perform actions in the server after all client have received the new value of the variable. For example I need to set the current player after all players received this new value.

 

You can have each client call a ServerRPC and the server counts how many clients have sent their "receipt" status. The server would have to maintain who sent a receipt.

However, this sounds more like you should do it with RPCs altogether. Call a ClientRPC and have each client respond with a ServerRPC to confirm the receipt of the value.