The eligibility criteria for UPSC which is the entrance exam for Civil Services is that you should have completed your Bachelor's degree in any discipline. So if you are not interested in pursuing BA, you have a variety of courses to study from. They can be Professional courses like MBBS, BDS, B.Tech, CA, CS or life Science courses like B.Sc in Bio Technology, Microbiology, Biology or Mathematics, Statistics, or Acturial Sciences. It more or less depends on the subjects that you have studied in your 12th. If you can help us with that information, we can help you with relevant information.