I couldn’t put the entire name of the native in the title: GetVehicleMaxNumberOfPassengers
It’s boring. Every time I need to get the maximum number of passengers, I have to do a callback from the client who is in the scope of the vehicle. It would be awesome to have this getter server-side when you are trying to create scripts with server-side authority
GetPedInVehicleSeat exists on server. Just make for loop from -1 to X. 
It’s the best solution.
The server doesn’t know the max number of seats for a vehicle, and likely never will, you should use GetPedInVehicleSeat like @itismaku said.
On the server the limit for the amount of occupants in a vehicle is hard coded to 32
Ok thank you i’m going to do that