( Akansha Singhal, B.A. (Political Science), Patiala, Via: E-Mail )
Dear Akansha, the answer is NO. It does not matter much. The minimum eligibility for taking up the Civil Services Examination is pass percentage in graduation.
The evaluation system in our country is not standardized. You could easily score a 4.5/5 from some local degree college, but a 3.5 from some reputed institutes is a challenge in itself. The diversity of fields of candidates attending the UPSC interview, does not allow for a simple comparison of degree percentages towards the merit.
UPSC is not looking for scientists or academicians. The merit of a student in graduation is no indicator of his/her success in his field; forget civil services or life in general. You could easily land in the top percentile by choosing your electives smartly (read lecturers who give easy grades). While someone passionate about the subject may pick electives of professors who are stingy with grades but amazing at imparting knowledge.
Many aspirants having less marks in graduation have passed Civil Services Examination.