Hi Kanchan,

It depends on your school. PCMB option is available in almost all of the schools, but it might not be there in your school. Also, I would suggest you to think for a while and go with PCM or PCB as taking PCMB means you will be carrying an extra load on yourself. As in medical there is very less use of mathematics and in engineering there is no use of Biology.

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!