[rjjj]

The PutPlayerInVehicle function have to have 3 parameters, and you put only 2

I think that car1 and car2 are global variables, so, let's go.

Look, i fixed it for you:

pawn Code:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if(strcmp("/ready",cmdtext,true,6)==0)
    {
        if(IsVehicleOccupied(car1))
        {
            PutPlayerInVehicle(playerid, car2, 0);//There was only 2 parameters
        }
        else
        {
            PutPlayerInVehicle(playerid, car1, 0);//There was only 2 parameters
            TogglePlayerControllable(playerid, 0);//This line freezes the player that used the command
            return 1;
        }
        return 1;
    }
    return 0;
}

I hope that i have helped