Civil Servant (IAS/PCS) eligibility

Yes, from any field, if you have completed your graduation then you are eligible for this exam so you just need to prepare well to crack this exam.
All the best.

A degree of any of the Universities incorporated by an Act of the Central or State Legislature in India or other educational institutions established by an Act of Parliament or declared to be a Deemed University under the UGC Act, 1956, or an equivalent qualification.
Candidates who have appeared or intend to appear for the qualifying examination and are awaiting results are also eligible to appear for the Preliminary Examination however, they are supposed to submit proof of passing the requisite qualification along with Detailed Application Form for Civil Services (Main) Examination.

BCA degree holders from recognized universities are eligible to appear for civil services examination conducted by UPSC to become an IAS officer.

You must have attained 21 years of age and you must have a graduate degree from recognized institute. You will be given IAS or IPS according to your rank.

No u cant give. For giving IAS exam 2017 u should be 21years before 1august

Education Qualification: must hold a PASS Bachelor'S degree from any of the Universities
Age Limit: must have attained the age of 21 years and must not have attained the age of 32 years on the 1st of August, 2016
more details: http://www.upsc.gov.in/exams/notifications/2016/CSP_IFS/CSP/CSP_2016_Engl_Notice.pdf

If you want to give the exam your age should must have attained the age of 21 years and must not have attained the age of 32 years on August 1 of the year of examination. Prescribed age limits vary with respect to caste reservations. For other backwards castes (OBC) the upper age limit is 35, and for scheduled castes (SC) and scheduled tribes (ST) the limit is 37 years.

Hello Rahul, you are not eligible for IAS in 2016.

There's no bar on minimum percentage of marks.

Yes you can take up UPSE after your degree.