Dr. B.R. Ambedkar Open University (BRAOU)

You can pursue Graduation through distance or Correspondence mode.

Atleast you must have 75% to be eligible for anything.

Hello Dear,
Yes, you are eligible for it.

Yes, you are eligible but I am not sure why you want to shift from masters in technology degree to a masters in science because it is out of the regular curriculum but anyway best of luck.

For Indian citizens, you can directly apply to the course on their website, provided your Diploma is equivalent to 12th.

Yes, you can go for a nutrition course, but you will have to do your graduation all over again, as you start back from B.Sc, which is an undergraduate degree. So, if you feel you are not satisfied with B.Tech and now want to switch over to nutrition, then sure go ahead and live your dreams.

With a certificate course it won't be that easy to become a nutritionist. I would recommend, an advance Diploma or Bachelor's. But, a certificate course could be useful, depending on its value.