CBSE 12th

Hi Ganesh,
Many options are there from Diploma to Bachelor's degree. For better career prospects go for a Bachelor's degree. See this:
https://www.shiksha.com/search/?q=Sound+Engineering&sp[]=477&sa=^0^0^477^0^0^0^0^0^0^0^0^0^sp:477&rf=searchwidget&pn=1&sscs=1&tk=sound+en&ii=1&s[]=7&tscs=1

Hi Adish,
If you have a strong profile and manage your finances you should at least try applying to a good university abroad. If you manage to get into IIT, NIT or BITS then you stick to India. You have to compare, go abroad if it's a reputed university.

Hi Sameer Pk,
Yes, you can study from the Netherlands. Scholarships will depend on the university though you should also check Erasmus Mundus Scholarship to study in the Netherlands. Visit their website for details. Check university websites also for scholarship information. Remember you have to take IELTS too.

What is RIOS? Please give the full form.

Many of the forms come out before the result for class 12th gets announced, so by the time your result is out, you can definitely apply for your desired course.

You might get NIT - Srinagar, Patna but you should focus on advance.

So, you have big gap in your studies. So, I will like to suggest you that you should take admission for 12 arts external because its not possible for you to do regular lecture as you must be going any job after 12 go for B.A. External and you can finish your graduation in 4 years without any gap and studies are also easy. There is one tip for you that prefer to take your admission in your mother tongue only it will be easy for you.

Sorry, as you said you are out of date now you can't apply for CET.

If you have keen interest in Maths, so I must say you should choose B.Sc after your class 12th, and go for research. Else, if you are interested in economics, just do BA and then, Masters in economics. That is also fabulous, or else after graduation prepare for UPSC or SSC exams get job and settle in life. Geography is also good subject so follow as like economics. All the very best.