My husband told me this true story that happened in Bnei Brok. A few principals of a yeshiva came to Rabbi Schach and asked his advice…they wanted to kick out a child from their yeshiva. Rav Schach asked them if they knew the boy and his background and they didn’t know…just that he was acting up and not behaving in yeshiva. ROTZCHIM! MURDERERS! said Rav Schach, you are ready to kick out a child without a clue why he is behaving this way? The principals looked into the matter and found out that the boy’s parents were getting a divorce. and they kept the boy in their school.
If a school kicks out a kid from school, they are giving him a death sentence. No school will want to touch him and he will most probably become off the derech.
If a school feels they are unable to handle a particular child, they should try their best to find a school that does accept him and is willing to give him the extra attention he needs.