My suggestion Go for BCA or Bsc (IT ) where you can get in computers rightaway or else try any entrance which asks  Computers in the entrance . 

  Or else if you can aford go for SAT and prepare for the exam and Join BS comp science in US .

Dropping a year is not an abosolute requirement , He can go for BS straight away , I belive his intelect and interest in computers should not be disturbed by whole of a year and than thinking about the loop holes in present engineering education What if he could not make it to comp science or he compromised in branch and landed in Electrical or mechanical the result will be either the engineering at the cost of his computer or Computer at the cost of the studies it better to go for SAT now .

     How ever I am not fully against dropping a year . He can go for that also Preparing for the entrance away from his favorite toy again ether the entrance at the cost of the computers or the computers at the cost of the entrance How can I be sure to say taht if he has not shown any interset in 12th .