Hello aspirant,

YES, As per my knowledge, you are eligible to apply for IES exam after completing Diploma in Mechanical Engineering and qualifying AMIE exam .

The Eligibility Criteria for Indian Engineering Services (IES) is as follows:

Candidate must have passed degree from a recognized university. 2. The age of applicants should be in between 21 to 30 years.

Furthermore, to know more about the UPSC IES exam you can follow the below mentioned link to know more about it : https://competition.careers360.com/exams/upsc-ies/iss

I hope that this will help.