Technically you should be allow to chose this course as Maths (Advanced) is only for those who want to pursue PCM in class 11th and go into the technical fields. You can always request to your principal that according to CBSE, you cannot be stopped from taking Arts with Maths and if you are still not allowed then you should either change you school or complaint about this to CBSE as you should always fight for your rights!

Hope I have answered your question. All the best!