Child behaviour

Patient: My six year old son seems to be lost in his thoughts.. Wenever i ask him ( i wuld say its 7 out of 10 times) he either wont listen or he will sat i cudnt hear.. But he is very gud at school he is one of the best three students in his class.. I have two sons the youngerone is four and is talkative and aggressive too.. But he my elder son who is six seems to give up easily.. Its not that i am comparing or i am partial at home but because of this behaviour he suffering with his frnds too.. He feels sad after his playdates.. He shows his anger frustation (verbal) on me only.. Wat should i do.. I do get angry sometime but i am working on it. Pls help.. Dont want my child to be shy and introvert..