Is it possible to change the number of touches in Android 6.0 without root? The default is 2, but I need 3 or 4.
Each phone's touch screen has a limited amount of touchpoints. As far as I know, nowadays all the smartphone has a maximum of 10 multi-touch points. Whereas, the older phones will give you almost 5 multi-touch points. I think there is a mistake in counting your multi-touch points. I hope your phone has a minimum of 5 multi-touch points.
Unfortunately, there's no way to increase or decrease multi-touch points no matter your phone is rooted or not. Nothing can help.
It's the hardware that has a limit and it's controlled by software. And software has to obey the instructions using the limited ability of hardware.