DRDO doesn't specify the GATE cutoffs. You see its a defence organization and the information from it is pretty minimal. However since it is a highly coveted job, the GATE scores are high as per reports from students. You can check the GATE scores for many PSUs herehttps://engineering.careers360.com/articles/what-are-gate-scores-for-psu-recruitment. If you notice the scores given by many PSUs are on the higher range. So you may expect that it will be more or less the same. The only plus point with DRDO is that they recruit on the basis of valid GATE scores. So in 2016 they took candidates on the basis of 2015 and 2016 scores unlike other PSUs.

You can consider below details -

BARC - As of now, the application dates are not yet declared but tentatively the registration will be starting in fourth week of January 2018.

DRDO - Application forms will be released in third week of March 2018

ISRO - There is nothing announced for the same as of now.

Also, I would suggest you to stay tuned with us on below provided website to know all latest updates for PSUs important dates -

http://www.engineering.careers360.com/

Hope this helps!!!!

In order to become a scientist you should have analytical and critical thinking skills.

You'll need to be well specialised in mathematics. Scientists in the physical sciences use a great deal of mathematics, particularly algebra, calculus and analytical geometry, while those in the biological sciences use math less often. All scientists need a working knowledge of statistics, too.

You need Skill in one or two foreign languages. The most helpful languages to learn include French, German and Russian.

If you want to become a scientist at NASA, then you must choose science, technology, engineering and Mathematics centered education. You can do B.sc or B.tech in your graduation. 

Below are the top colleges you can check

• Indian Institute of Technology (IIT), Delhi
• National Institute of Technology (NIT’s)
• Indian Institute of Space Science and Technology (IIST)
• Indian Institute of Science (IISc)
• Indian Institutes of Science Education and Research (IISER)

All the Best!!

Check their official site: DRDO internship You will get many posts for UG and PG level and check whether there are possibilities for internship as well.

Or else you can even visit the centre and ask for the dates regarding forms for training/internship.

Good Luck.