How can I prepare for the IAS Exam without joining any coaching while doing my undergraduate in a BSc in mathematics at Kolhan University?

Yes, it’s not possible to prepare for the IAS exam while pursuing your undergraduate degree from Kolhan University. Studying at Kolhan University gives you an advantage over other universities, as you don’t have to attend regular classes. 

You can utilize the time and self-study. Start referring to NCERT books for classes 6 to 12 standard. Develop a habit of reading newspapers regularly. You can read The Hindu or Indian Express. Chalk out or make specific notes after completion of the reference books for later.a