NIOS 12 th

Yes, you can surely apply for admission in DU after completion of your class 12th from NIOS board, there is nothing to be worried in it. But, you will only be provided admission if you do fulfill the admission criteria as the criteria for admission in DU is always quite high due to its reputation. Therefore, your only concern should be of marks and not that from which board have you completed your class 12th in.

Hi,
As per questions, yes, you are eligible to take both Mains and advanced test. But to take admission in IIT, the minimum eligibility for you to take add admission is that you have to score 65% in 12th boards. So, go for it. All the best for future.

You can search about the college whether they take admission from NIOS or not in abroad.

Yes, you can pursue this course.
Eligibility for applying to the college is as below.
Candidate must have passed 10+2 from a recognized board.

If you had passed board exam, and want to upgrade your education then you can apply for 4 subjects or a single subject. But, if you fail in board exams and applying for single subject admission will be rejected.

Yes, NIOS degree is accepted in every college.

Yes, students of NIOS are accepted in Anna University.

Hi Debmalya Das,
Yes. You can apply for the course.
Please check the Eligibility as below:
1. Minimum Eligibility to Apply-Qualification: 12th with 40% minimum
2. Additional Details
Mandatory Subject : English
3. Other eligibility criteria
Candidate those have BPP with PSS with 50% marks in aggregate from NSOU are eligible.
OR
Candidate must have passed 10+2 in Vocational Courses with 40% marks in English from a recognized board /Institute.

Yes, you can join NDA after completing your schooling form NIOS and from a recognised board with science stream.
Good luck.

You can apply for all the type of government exams available after 12th. So don't worry. You can apply for clerical jobs, defence jobs, etc.