UK

Among these three, Australia is the cheapest. And the fee structure depends upon the course.

The score depends on the programme. What scores are you looking at?

There are plenty of Masters in management programs on offer in UK. Most of them would be for a period of 1 year. Almost all the universities in UK have that programme on offer.

Yes, you can apply as you are not having any Indian degree, so this will be easy for you to do it well.

Yes, you can do MS in UK after you finish your programme. And IELTS. So, the first thing for you to do right now is to concentrate on your degree. The last 2 years are especially important. Try to score above 70 percentage or equivalent. Then soon after you finish your UG there would be a small period of waiting for your degree certificate. If so. Get some work experience while you wait. Then once you get your degree certificate. Appear for IELTS. Then apply for any university you like in UK.

Yes, it is, but provided you study at a government recognized educational institution in UK, but have it verified with the college as well.

I think apart from having an excellent academic record, you are required to have a GMAT. Check the entry requirements of the universities you are looking at.

Consult with immigration authorities and find out the recent trend.