Yes you can take up any stream in class 11th and 12th. Just start reading leagal aptitude and reasoning later start maths and English for the entrance exams of law for example CLAT.
You can switch on career 360 notifications on law entrance exams so that you are notified immediately when when application forms starts.
All the best do well
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile