Hello Maria,

No dear, you cannot take admission in science stream in class 12 if you have been a student of commerce stream in class 11.

As the option for choosing or alloting the streams to the students is provided in class 11 itself and not in class 12, so you cannot change your stream on future.

You will only be eligible to take science in class 12 if you have opted for it in class 11 as well.

Hope it helps.

Good Luck!