Hi Raj

People who did engineering in Environmental Engineering domain can chose to write GATE exam in either Civil Engineering domain or Chemical Engineering domain. It is choice of the applicant. But it is mostly recommended to write GATE exam in Chemical Engineering domain, so that even the syllabus in the exam, job roles which are offered after getting through PSU interviews and syllabus of environmental engineering go hand in hand. 

If an applicant clears GATE cut off according to his/her cateogary and if they get good rank then they are eligible for M.Tech admission process in IIT's and NiT's and also an excellent GATE rank accompanied with very good personal interview would easily fetch candidate a Public Service job role.

PSU's Which consider GATE score in Chemical Engineering:

• BARC
• ONGC(Oil and Natural gas Corporatation Limited)
• IOCL (indian Oil Corp.Ltd)
• HAL (Hindustan Aeronautics Limited)
• BPCL (Bharat Petroleum Corp.ltd)

PSU's Which consider GATE score in Civil Engineering:

• AIA (Airports Authority of India)
• HPCL
• IOCL
• NFL (National Fertilizers Limited)
• NLC India Limited
• ONGC (Oil and Natuiral Gas Corporation Limited)
• PGCIL
• THDC India Limited