as your friend want to know scope of Indian Engineering Services, so here I am telling that applicant who clear the Indian Engineering Services Examination are then eligible for employment in the different departments which are under the Government of India related to engineering.

Here I am telling about post under various department:
Departments for Mechanical Engineers after IES

A candidate from Mechanical Engineering can seek employment in Group A in following departments.

Central Power Engineering Service

Indian Naval Armament Service

Indian Railway Service of Mechanical Engineers

Central Engineering Service (Roads) Indian Navy

Geological Survey of India

Indian Supply Service

Central Electrical & Mechanical Engineering Service

Electrical and Mechanical Engineers, a branch in the Indian Army

Indian Defence Service of Engineers
Departments for Civil Engineers after IES

Aspirants who have specialization in Civil Engineering will be appointed as Assistant Executive Engineer in following departments.

Indian Defense Service of Engineers

Indian Ordnance Factories Service (IOFS)

Central Water Engineering

Indian Railway Service of Engineers

Indian Railway Stores Service

Central Engineering Service

Central Engineering Service (Roads)

Border Roads Engineering Service
Departments for Electrical Engineers after IES

Applicants who are Graduates in Electrical Engineering will be appointed as Assistant Executive Electrical Engineer in following departments.

Indian Railway Service of Signal Engineers

Central Power Engineering Service

Engineering Service (Electrical Engineering Posts) Indian Inspection Service

Indian Defence Service of Engineers

Central Electrical and Mechanical
Departments for Electronics & Telecommunication Engineers after IES

Those who have completed graduation in Electronics & Telecommunication Engineering can seek employment in following departments as Grade 1 engineers.

Junior Telecom officer in Indian Telecommunication Service

Indian Railway Stores Service (Telecommunication/ Electronics Engineering Posts)

Central Power Engineering Service

Assistant Naval Stores Officer Grade- I

Indian Inspection Service Group

Indian Telecommunication Service