No student you can't do that as You can calculate the aggregate of your marks by adding the total marks scored by you of each of your subjects and dividing it by the total number of subjects. This will give you your overall percentage. Your main subject should be PCM and English if you're calculating it for engineering. Plz help me with the course you're interested so that I can provide you exact information.

Also
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Feel free to comment if you have any doubt
Good luck