The status of this response is Pending and require some modification by the author.
If you are taking admission to a school that strictly follows CBSE rules , then you should not be forced to take mathematics as one of the compulsory subjects, for the Science stream.
To proof this you can refer to the following link, from the CBSE official website, from where I have taken this snippet.(http://cbseacademic.nic.in/web_material/Curriculum19/InitialPages/Senior_Secondary_School.pdf )
"Science and Technology (Subjects related to Biology, Chemistry, Physics,
Computer Science Information Practices) include gaining knowledge
about matter and energy, nature, the environment, technology,
breakthroughs in science. "
When you visit any of the schools you want to take admission, talk to the principal about this rule and share with them the above mentioned link.
Mathematics is a separate subject altogether offered for the XI-XII course, where again this following snippet states the current rule of CBSE, that you will find in the same link as mentioned above in the next paragraph.
"Mathematics includes acquiring the concepts related to number sense,
operation sense, computation, measurement, geometry, probability and
statistics, the skill to calculate and organize, and the ability to apply this
knowledge and acquired skills in their daily life. It also includes
understanding of the principles of reasoning and problem solving. "
If the schools don't agree, you can directly contact the CBSE through their official website http://cbseacademic.nic.in/ and ask for their advice. You can even name the schools where you have tried for admission.
However, earlier the science stream did include Mathematics as one of the compulsory subjects, if you wanted to take science as your stream of study. As all the basic subjects of science has some part of mathematical component inherent in them, it was regarded as an indispensable subject, when you study science. The basic concepts of mathematics help in developing better understanding if other subjects as well, but as Mathematics too got deeper in its own realm, streaming away from other science based subjects and involve a whole lot of theories and skills, people who do not have a knack in this subject, but is keen on other science subjects can now choose science without having to study mathematics as a part of their syllabus.