You definitely are eligible to appear for the IAS exam. In order to appear for the UPSC Civil Services Exam, all you need to hold is a graduation degree irrespective of the marks you secure in your graduation. However, you must meet the age criteria which lies between 21 to 32 years of age. Candidates belonging to reserved categories will be given age relaxation upto three to five years. You must go to UPSC CSE eligibility criteria in order to get more details related to the eligibility criteria.
There is no aggregate percentage required to score in your graduation to be eligible for IAS examination. You only need to possess a graduation certificate from a recognised university to be allowed for the entrance examination. You must also be atleast 21 years of age for taking this examination though the upper age limit is 32 years which is subject to relaxation for 3-5 years depending on the reserved categories. If you possess the details said, then you will be eligible for IAS examination.