What is the eligibility criteria for appearing in IAS examination? Which course should I pursue after completing my class 12th?

Hi, The candidate must hold a degree of any of Universities incorporated by an Act of the Central or State Legislature in India or other educational institutions established by an Act of Parliament or declared to be deemed as a University under Section-3 of the University Grants Commission Act, 195

You can prefer any course for your graduation but if you chose courses that come under optional papers it may help you in Mains exam of IAS. For further details you can refer here: https://www.iassolution.com/ias-exam-pattern-eligibility-syllabus/