Government & Defence Entrance Exam

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

If you are taking about NDA 2 2018 then yes you can get call letter, chances are high since you are clearing sectional cutoff for maths as well as GATE which would be around 25%.

Refer the official website of SSC there you can get the notice for the CHSL. In the notice search for the syllabus section. Don't attempt too much questions on guesses. Try to attempt those questions on which you are confident. Don't try to attempt the whole paper. If 160 questions are there at least make a goal of attempting 80 questions correctly.

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.

You can go through agricultural science or biotechnology. Now in India these two fields are growing and the demand is increasing day by day.

According to your question, yes, definitely you will be allowed to appear for SSB and even to be selected for it as well. SSB has nothing to do with your medical condition, if you have qualities of an officer then you will get selected. Moreover once you clear SSB the task of checking your body well-being is with medical board. If they found any medical problem then you would be rejected. For checking the medical condition accepted, I advise you to Google it and see it from official site. They will provide you with all information.

Definitely, NDA is one among the best option after class 12th. Getting selected for NDA secure a job in the elite arm forces of India which is respected in and out of the country. Moreover, you live a life which not all get to have. You have perks of an officer.

For getting admission in NDA you have to appear for its written exam first. Moreover, for getting officer's post in army you can apply for TES entry of army which has direct entry and call up letter is based upon class 12th marks.

You just have to be natural over there, don't try to fake yourself, have good stamina, be up to date with current GK and read about the basic procedure. For more information refer www.ssbcrack.com.