Question: i have 4 /12 year old son studying in lkg. Off late he has become more aggressive

I have spoken to the class teacher also. She has punished him many times and even she pampered him. She has tried to make him understand how it hurts others. I will stop beating him as you said. I have even tried to ask him when he is cool for example the other day he broke one of his class mate's ear aid.When i asked he told that he thought it is a toy. I even checked with the lady who takes care of him in our absence after his school. She told me that he has lunch and goes to sleep for 4 to 5 hours. then gets up and does his homework and watches tv. Sometimes he tries to do some mischief and she tries to correct he does not listen. Even at home i try to stop him calmly also he does not bother. Often he does not reply if i advise him. Pretends as if he did not hear what i have told him. He is stubbon at times. Like yesterday i took him for shopping he started asking for a finger ring. He has seen his father wearing for office. I told him not to wear gold ring for school. He made such a noise on the road and even in the shop till i could buy he started hitting me back with the plastic bat what he had and i was very calm and tried my best to stop him. He even tried to bite. I did not allow. After a long time he became calm. It was very difficult for me to handle him in the public. Last week also he was biting teeth and was trying to hit me back in a shop. I took him home. Later he himself became calm. When he realsied that i am not speaking to him. He started watching me for sometime and tried to ask why i am quiet. Then i told if you keep on hurting others. I will not speak. Then he said he will become a good boy. Again he started the same thing yesterday i.e after two days. If we try to correct him or try to stop him from doing something. He does it more. two days i took him out for park then made him play with other children in the neighborhood. But found him more stubborn and was trying to do everyone on his own and was not allowing others to play. I even saw him slapping his friend because she insisted her father to buy ice cream and i told her not to have since she gets throat pain He heard me telling her not to have and he went and slapped her saying when mama is telling you not to have why are you forcing your father to buy. His teacher is fed up with him. Even at times i am not able to control. His father has slapped him two to three times for throwing things in the house and not listening anyone. He loves watching cartoons which are more aggressive like power rangers. Please doctor how to deal with him. I am scared where his school management will suspend him as i have taken lot of trouble to admit him to this school. Please guide me. If i tell his father there is no use. He does not like him showing him to a psychiatrist. Unnecessary arguments will crop up in front of son which i dont want to do.. Please guide me.
In continuation to my previous question, if i ask him about his behaviour in the school he keeps lying saying teacher has told he is very good. I thought he must have changed. After two weeks i went and met his teacher and got to know that he is troubling too much and she is not able to control. She was feeling very bad for punishing him also. Saying out 48 students in the class if anyone asks who is the smartest kid she will prefer my son. I am very much worried about him doctor. kindly help.

Thank you doctor for your suggestions. We will definitely follow. I will try my best to change him calmly as by your direction. As it might take sometime for him to behave normally, i have a concern in case if he happens to repeat this again in the school and the management decides to take some action what should i do. As his teacher has tried to take him to the principal thrice last week. He got scared and told he will not repeat but again started same thing. I am worried it should not effect his career and one of my husband's friend's son who is in 7th standard used to behave same way finally the school management suspended him. Kindly advise.