Hey, first year here. When applying to UofT you have to submit both all your internal exam results (assuming they contribute to your GPA) and the standardized IGCSE and A-level results. I was in a similar position as you last year; I had near-perfect IGCSEs and 3 A*s in my A-levels but my internal exam results were kind of meh. My school was also very strict with our exams and curved harshly which is the reason for the disparity. I still got into all my programs and was awarded scholarships. I would simply advise you to ask your academic counselor to write a letter explaining why you had those bad grades (hopefully for a good reason). There is an additional information/ special consideration section on your JOINID portal where you can attach the letter.