If you are good in science and maths, continue studies in science stream with PCMB. With this option, you can do MBBS and become a doctor or do engineering. I would suggest that you go for microwaves and telecommunications or aerospace engineering. You cannot get admission for MBBS unless you score high marks in 12th (science stream) with PCB. If you take PCMB, all the options i.e. medicine, pharmacy, engineering are open to you.
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Yes you are right, it always happens; everyone is confused whether to take the extra subject or some other subject. Well as you say you are good at Science & Maths then you could do one thing, take PCMB as your subjects for the 11th and 12th. During this period you could judge your self as to which interest you most. It will have all your options open once you give your 12th Board Exam.
Hey you could also ask for counseling on this site
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