Hello Pavan!

Let me tell you first about IISER exam pattern. IISER exam consists of 4 section: Physics, Chemistry, Mathematics and Biology. There are 15 questions asked from each section for the total duration of 3 hours of the exam. 3 marks are awarded for every right answer and 1 mark deducted for incorrect answer. No marks awarded or deducted for unattempted questions.

Now, it is not compulsory to attend math section, however, if you dont attend, then you will be loosing 15 marks for sure. So I suggest you to study math too. Join any coaching centre or if you can study on your own. There are several materials available online now.

https://engineering.careers360.com/articles/iiser-syllabus-exam-pattern

Refer to this article to know about IISER syllabus.

All the best!