Please check the following additions in class XI and class XII Mathematics syllabus (CBSE). Remember that these are provided by CBSE in the form of supplementary books and not given in main NCERT textbook. Get the supplementary book (quite difficult to arrange) or take out print out of the attached files. Also, do inform your Maths teacher to teach following subtopics (in case they are not aware).
Infact there are certain additions in other subjects too. Please check the following link from CBSE site to know the same.