India

I don't think options are available in US , you will find only MS or integrated Ph,D , graduate certificate courses are available in few universities but you need to hold an advanced degree for the same. If you are not interested in Masters there is no reason to prepare for GRE. Instead look for PG Diploma courses in Australia, Canada or New Zealand. You need to decide what you want to study and prepare accordingly. Check University of Michigan - Dearborn, University of St. Thomas, Minnesota and Boston University for Graduate Certificate in Engineering disciplines. Best of Luck.

Check the predictor below :
https://www.shiksha.com/jee-mains-college-predictor

Yes, you must take GRE and TOEFL. Also be aware that there is no government college. They are known as public or state universities. Other than these, they have private universities. You may also not find M.Tech. The degree notation is MS. Best of Luck.

Check the link below and filter the colleges according to location :
https://www.shiksha.com/top-automobile-engineering-colleges-in-chennai-rankingpage-51-0-0-64-0

Check the following link :
https://www.shiksha.com/top-engineering-colleges-in-maharashtra-rankingpage-44-0-114-0-0

IHM Kolkata is the best.

You can refer this link for colleges:https://www.shiksha.com/mba/colleges/mba-colleges-in-maharashtra

There is no term called Science journalist. You can become a journalist and then select Science as your beat. This way you will be able to cover all Science stories. Join Bachelor in journalism and mass communication after 10+2 and become a journalist after that.

National PG college, Lucknow is well known for its commerce courses.