I want to know a quranic amaal, for both of my boys, ages 3 and 5.
Both of them have severe behavioral issues. The older one has autism and is five years, but doesn’t speak anything and doesn’t understand complex language also.
The younger one is 3 years, has sensory processing disorder, and has severe severe tantrums to the point of hysteria and it becomes extremely difficult for me to control them.
Please tell me some quranic amaal or some surah which I can write and put it as taweez around their necks.

I’m sure that you already would have sought medical advice.

You can also read this Dua:

https://www.duas.org/sajjadiya/s25.htm

Also it is recommended to read Suratul Ahzaab (33) of the Quran.