Firstly great thought that you want to become an IAS officer. There is no problem in quitting science and continuing your education with commerce you can have a commerce degree and can also apply for UPSC examination. Some of the bachelors degree you can get in commerce are :-

1. Bachelor of Commerce (B.Com)

2. Bachelor of Laws (LLB)

3. Chartered Accountancy (CA)

4. Bachelor of Business Administration (BBA)

5. Bachelor of Financial Markets (BFM)