If u are going in field of engineering than u have to opt PHYSIC,MATHS AND CHEMISTRY with English as a compulsory subject and after that u have the choice to select from below mention subject as your 5th subject. Computer Science. Physical Education.
Other than that some schools may offer a choice to select six subject(6th subject as additional) which may help u to score better percentage in class 12 board exams.
So u have opportunity to select six subject then I advice u to go for it as it may help u to increase the percentage and it will not going to be a burden to u as u can study the 6th subject (physical education) in just 5 to 10 days and also u will score 90+ in that