Hi

No, it is not compulsory to have 6 subjects in your CBSE class 11th and class 12th but yes if you want ,you can definitely go for 6th subject and if you have it then it will be your additional subject as there can be only 5 main or compulsory subjects.

Again,

Whether you can have physical education or not depends upon your school whether it offers physical education or not ,if it offers then you can definitely have it as your 6th subject otherwise you need to go with the subjects offered by your school, so you need to check with your school once. In case if you don't want to keep any 6 subject then you can go with 5 subjects only as well.

For example,

I have studied from cbse board and I had taken 6 subjects i. e 5 main subjects and one additional subject i. e 6th subject whereas my friend did not opt any 6th/ optional subject and did 10+2 with 5 subjects only. So, whether you want to have 6 subjects or not completely depends upon your choice.

Thankyou