Hello!!!

Well it's good to hear that you are planning to appear for JEE MAINS again. You can  leave your current course and give jee mains  and if you clear it ,you can get admitted to the same institute or some better institution. You can change your branch also if you clear it. But leave your course only when you are sure about your new institute and you are satisfied with after after the allotment of seat or mock seat allotment.