B.Sc

Hi there,
In order to get the requisite information, you need to mention the college or university preferred.

Selecting back home over B.Sc. Is a quiet good thing and if the institute is CHANDIGARH UNIVERSITY then it's a well good combination for a bright future. So, it's a good option. For further details:
http://www.cuchd.in/agricultural-science/bachelor-of-science-bsc-agriculture.php.

You first need to decide on your interest areas and long-term career objective then keeping both in mind decide to pursue further courses. There are a lot of certificate & Diploma courses in multiple areas that can enhance your chances of getting a job. Some of the areas are- data analytics, graphic

JEE Mains is held only for admission to NITs, IIITs & other GFTIs. There is no such JEE for B.Sc.

Yes, you are eligible for NIMCET, because you have a graduation degree along one subject, as a computer Science.

Yes, you are surely appear in competitive exams. Eligible criteria for these competitive exams is you should have your graduation degree.

Hello
Here I mention a link given below please visit on it
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor&ved=2ahUKEwjGue-Wh_vbAhUK6Y8KHVA9D1kQFjAAegQIAxAB&usg=AOvVaw1N9BzFtyUCP4JU-2UQHQ0H.