Engineering

There is no huge difference, but yes it is different from your 3rd year of B.Tech.
In IT, it is all about Software, in CS it all about Sofwtare + Hardware + OS core. So, choose the same as per your interest like in software/programing language or in IT infra like network/server/Operating System etc.

Aeronautical engineering has a good scope now, and also salary is also good.

No, you can not apply for these government exams, you should qualified your graduation degree, then only you can apply for this exam.

The minimum requirement in JEE Mains is to get admission in NITs 94 percent or 95 percent.

Hi,
Please refer to the link below:
https://www.shiksha.com/b-tech/course/b-tech-in-civil-engineering-karnataka-state-open-university-lucknow-163519

You need 7499 points on Shiksha platform to reach the guide level 12 and for that you need to provide high quality answers and also your answer count should be big and useful for others.

Hi,
You should contact the institute directly for the guidance. They will be able to assist you well http://www.tmi.tolani.edu/contact-us/

Hi,
Please mention the college to get exact guidance.

Both the courses have equivalent scope and opportunities in the future, but as per my knowledge B.Tech in agriculture is more technical oriented study. So, I would recommend you to go for B.Tech in agriculture.