Nagaland

Sorry, you are not eligible for B.Ed.

No, you can't, because 45% is not expectable. If you are a general category student, 50% marks is a must in B.Ed. I want to do the same.

Admissions are closed now.

The course fee is about INR 27,200 mentioned on a site, which provides the information on the college.

First of all, congratulations on clearing JEE Mains and among these low ranked NITs, I would recommend Sikkim followed by Srinagar, Manipur, Nagaland and Meghalaya.

These NITs are not good in terms of placements. In my view, you son should get admission in a good deemed university.

OUAT Entrance Exam 2018 Eligibility
The minimum education qualification to pursue a B.Sc course at Orissa University of Agriculture and Technology states that aspirants should have pursued their 10+2 with Science and secured minimum of 50% aggregate marks including extra optional. For candidates who have applied for admission under SC/ST/PH category need to have secured a minimum of 40% marks in their qualifying exam.
Please refer to the link provided below for further details:
https://www.shiksha.com/science/exams/ouat-entrance-exam

Please refer to the link provided below for a list of M.Phil courses awarded by Global Open University, Nagaland:
https://www.shiksha.com/university/the-global-open-university-nagaland-other-4529/courses?bc[]=98

You can do your B.Ed both in regular or distance mode. As you are working in a government school, you will get 2 years deputation period to complete your B.Ed. Otherwise, you can choose IGNOU for distance education.