Hello ,

I hope you are doing well. As per your mentioned query, if you want to repeat your class 11th with different stream yes you can do the same. It is legal and you can repeat your class again by same board or different board.

To know more about this, kindly go to the link where you can find out the cbse boards :

https://school.careers360.com/boards/cbse

I hope it will be helpful for you!!