Engineering

Yes, from today onwards, the registration has been started on the basis of JEE Mains and JEE Advanced for admission in IITs, NITs, IIITs and GFTIs.
Registration - 15th June to 25th June 2018
First round result - 27th June 2018.

Hello Jatin,
You have quite a good rank in JEE exam. Please go through the link below to predict best colleges based on your JEE rank. Through this link, you will find various colleges of engineering:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=C

Yes, definitely, you can go to the ISRO and NASA. In ISRO, if you are a Ph.D candidate, they offer a job without interview also.

Friend,
From the first year, you can join coaching centres to prepare for GATE exam or you can study yourself by solving sample papers while studying with books. Go for the link to get the tip for GATE preparation:
https://www.google.co.in/amp/s/www.shiksha.com/articles/amp/gate-preparation-tips-5-bes

Sure Atharv,
You can apply for admission in Dr. D Y Patil. The admission procedure is based on the counselling procedures. You should have to appear in counselling for admission.
Please go through the link below for more information:
https://www.shiksha.com/college/dr-d-y-patil-school-of-engineering-a

You can apply for Scientist/engineer category 'B' after B.Tech.

As per your IMU CET rank, you can directly get admission in RLINS, and there no need to go for counselling. Please contact 98940007317/7339132159.

Use the Shiksha college predictor for getting some idea about college that you might get through your valid JEE marks. For your help, I had provided the link. Click on it:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor