I am taking my alevels exams this may June session from lahore Pakistan.I m currently appearing for physics chemistry and maths.I wanted to go for any engineering field but oppurtunities for engineers here are not so adequate.So I want to appear for biology also and go for medicine.Can I do so?If yes then should I appear in this oct nov or may June next year?What are pros and cons

This is a question for your own teaching staff as we cannot possibly answer it.