B.Sc

The NOC is the abbreviation of "No Objection Certificate" which is issued by the university. You need this when you're going to do internship or training for a particular period of time. This document is required by the company in which you are doing your internship or training. Now, the migration certificate is given to you when you are leaving the institution permanently. This document allows you to continue your studies in another college where you want to take admission.

Dropping a year does not affect your career in any way. You can still get a college on the basis of your JEE Mains score & rank, even if you couldn't clear the exam, you will get engineering colleges of your state. Try JEE Mains college predictor to get more information and insight about the college which you can get on the basis of your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=4067795
If this could't work, then try to find colleges of your local state or city via directly searching it on Shiksha.
Hope this helps.
Best of luck.

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

There are over 4 Food & Nutrition colleges in Telangana. Please refer to the link provided below for a detailed list of these colleges. You should be able to navigate to a college of your choice using the filters on the web page. Regards. https://www.shiksha.com/science/colleges/food-nutrition-colleges-telangana.