Both are the good college. But in term of placement, faculty & industry exposure the best option is RMK Engineering college in the comparision of Hindusthan University.

RMK Engineering has AAAA rating which means very good & Hindusthan Enineering college has AAA rating which means above average college as per the analyzing report of Careers 360.

The companies visit to Hindusthan university are Infosys, Tech Mahindra, Amazon, Accenture etc. For further detail you can go through with given below link.
Hindusthan University Placement
The average package is approximately 3.5 to 4 Lakh per annum.

The companies visit to RMK Engineering college are ACCENTURE SERVICES PVT. LTD., AMAZON DEVELOPMENT CENTRE INDIA PVT. LTD., AMERICAN MEGATRENDS etc. For further you can go through with given below link.
RMK Engineering college placement

The average package is approximately 4 to 5 lakh Per annum.

You can also go through with the genuine reviews of the college you can go through with given below links.

RMK Engineering College

Hindusthan University

Good Luck!

Out of both the colleges, RMK Engineering College is rated as AAAA that is a Very Good college and Hindustan University is rated as AAA+ college that is a Good college.
Check the ratings for both below:

Hindustan University Reviews

RMK Engg College Reviews


The placements are good in RMK engineering college  than in Hindustan university though both are good colleges for engineering studies

You can check the placement report for both the colleges below:

RMK placements

Hindustan University placement report

The average placement is approx 4 lakhs in RMK college.
Good luck!!