An automatic car usually requires the transmission to be in park before it will start for safety reasons.
My car with automatic transmission will not start when in neutral and will only start when I put it in park because it has a switch on the shifting lever near the steering column.
If that switch were bypassed then it would start when in neutral but I never bypassed it.
I've had a few cars that would start when the automatic transmission was in neutral so it can depend on the car.
Also my car requires the brake to be depressed before the car will start as well for safety reasons in case a child decides to get into the car and tries to start it they would have to put there foot on the brake before the car started.
That same car also requires the brake to be depressed when you shift the car out of park which is also another safety feature.
Some cars with an automatic transmission will start when in neutral while other cars may not start when it neutral.
You can always try and see if your car will start in neutral though.