South Korea

There's not much difference other than basic few due to weather and the fact that Korea is a small rich country for a long time while India is a huge hot and not so rich country. Difference of economy makes huge difference in life style (for example desperation to look best even with the help of going under the knife) other than that Koreans and Indians are very similar.

First of all, you have to take admission in those college which provides the study exchange programme with the foreign countries if you want to study at low cost
This is one of the best options to study in South Korea
As from my understanding you should take admission in these colleges.

Yes but firstly you have to select the college/ university and then know the admission procedure of the college.

Yes, you can do that.

Yes, of course, I highly recommend you to choose your interest.