Yes, you can do B.SC in forensic science after completing your 12th class with PCM stream. With a little effort and a good knowledge of biology, you will be able to catch up soon in the forensic science stream.

But what I will recommend to you is instead of going directly B.Sc in forensic science you should do first your B.Sc in some pure science subjects like Physics, Chemistry and then you can do your masters in forensic science. This way you will also be able to live with your interest and will also be having lots of scope in your career. In India students who have got a degree in pure science subjects get more opportunities than the one with both the degrees in forensic science only.

Feel free to ask if you have any more queries. All the best!!