Certificate

I am not sure if the college offers a Spanish language course separately, but you can call the college and confirm. I will just share the number for you their number:
+91-11-27667747

Can you please elaborate what exactly do you wish to know about?

Yes, it is valid but not everywhere. Medical entrance exams like
NEET and a few government exams don't allow NIOS students to appear for the exam.

Hi,
To know about these details, I would request you to get in touch with the college officials. You can refer to the link for contact details: http://teluguuniversity.ac

Yes, you can join MGR Government Film and Television Institute for diploma in film technology with your SSC certificate.

You will most definitely need an income certificate. If your family income is less than 2.5 LPA or 1 LPA (will be dependent on what category you are OC, BC, SC, etc)., or else you don't need to keep any kind of income certificate if family income is above 1-2.5 LPA.

Well, if possible to get the certificate, you can go for it. But in most of the MBA colleges, they give some time about a month to submit your all pending documents. So, don't worry.

Most of the colleges in South Asia have similar curriculum whether it's Law, engineering, Literature or Science. Therefore, I believe it is valid in Nepal as well. As a matter of fact, a lot of students from Nepal come to India and study here and profess in their home country using an Indian university degree.