Which is the best branch should I opt to be a faculty or professor?

To become faculty in any university/ Institute you have to study up to PhD in your chosen subject. You can chose subject of your interest and excel in it to start your teaching career.

Dear Ruwaif, See You would be faculty in any stream whether in science, commerce or arts and there is demand in every field specially in teaching profession because very less numbers of students want to opt for Teaching. So you can choose the field or subject according to your interest and passion