Firstly, no degree is accurate for the UPSC aspirant. Studying for a degree course is different and studying for UPSC is different. So if you want to be a Civil Servant then you have to work hard only on the UPSC syllabus. Now Sociology and Political Science both are a fundamental subject and it can also influence your professional career. So if you wish to go for a course then I would recommend you to go for Sociology. Having a knowledge in Sociology can really give you advantage in your professional career. Political Science is also great but from Civil Servants point of view, Sociology can influence you better than Political Science. If you wish to be IFS then Political Science can give you some influence but for most of the cadres I would say Sociology will give you a better foundation to your professional career.

For UPSC Preparation tips visit the link below:

https://competition.careers360.com/articles/how-prepare-for-upsc-ias

To know more about Sociology visit the link below:

https://www.careers360.com/courses/sociology-course

I hope this answer helps. All the very best for your future endeavors!