Hey I am sharing the official aspirant portal link of Indian Economic Services with you. You should check it out. You will find all the details in this.

https://www.ies.gov.in/ies-aspirants.php

Educational Qualifications:

A candidate must possess Post-graduate Degree in Economics or Applied Economics or Econometrics or Business Economics from a recognized University. A candidate who has appeared at a qualifying examination, the passing of which shall render him/ her eligible to appear at the IES Examination, but has not been informed of the result, can also apply for admission to the examination.