Hello

As you are non mathematics student so it is difficult to get good score on maths. So first af all you need to know the iit jam syllabus and exam pattern . Syllabus is huge. So start preparing from the day one. So first go through all chapters of maths from board book. Then try to solve problems. And practice from privious year question paper. It you get any difficulty then take tha help of you tube.

Hope my answer will help you

Thank you