What are the legal rights for a school to suspend a child ?

Sir, This is just my question my son are 5 other students are accused of morphing a girls photo in the school which they didnt do. A student in their class tried to make the whole blame to my brother and 5 others. he says that they had a whats app group and there was the 5 students in it, and the photo was sent to it by one boy. The boy is confident that he did't do it. The girl child was upset and said to teacher the principle decided to search the phones of the 5 students which i think is illegal, but nothing was found in the search. the principle called us 'the parents'. when we went there he started showing all the old chat the students did about the school swearing about the schools things. and he yelled at us. One student was suspended because there was an image of him smoking cigarette in his house is there any legal things that i can say to school That they shouldnt have done or is there any rights for the school to suspend a child who smoke in the house. i hope you will answer these. it is just a quick question Thank you