B.Tech

Please check for your eligibility to appear for UGC NET from the criteria mentioned at the link provided below. You will have to opt for engineering sciences as your subject in the NET exam. Regards.
https://www.shiksha.com/teaching-education/exams/ugc-net.

There are over 239 B.Tech colleges in Delhi/NCR. Please refer to the link provided below for a detailed list of these colleges. Download colleges brochure, read questions and student reviews. Compare colleges on fees, eligibility, placements and other details at this link:
https://www.shiksha.com/b-tech/colleges/b-tech-colleges-delhi-ncr.

Yes, he is eligible for NEET 2018.

Hello,
You can go for the following data which will help you thoroughly. There are various scholarship programs are available just go through them.
Thank you.
https://www.university.in/sships1.aspx

Kindly visit this link:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

Nowadays, companies and also government focuses on network and cyber security and it has become one of the rapidly growing sectors of the IT industry. The average package will be 6 to 8 LPA.

Hello,
As per the following link, you won't get admission in IITs and NITs. You may go for private colleges or you can go for JEE once again for better college as well as for better stream. Core streams will not be available for you with given rank. Instead of getting any college and stream, you can try for next JEE.
Thank you.
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7589611

You should go for B.Tech in computers. It will help you to elaborate your interest in cyber security and cracking of codes.

Yes, it is possible to get admission in B.Tech on the basis of lateral entry. Eligible candidates are required to appear for the LEET exams. Engineering Colleges/Universities offering LEET admissions are:
* Punjab University - Chandigarh
* IP University - Delhi
* Delhi Engineering College - Delhi
* Punjab University - Patiala
* KIITS University
* Thapar Institute of Engineering and Technology - Patiala
* Government College of Engineering - Pune
* Punjab Technical University - Jalandhar
* Guru Nanak Dev Engineering College - Ludhiana
* Sant Longoval Institute of Engineering and Technology - Sangrur
* Anna University - Tamilnadu, etc.