UK

Dear Ananya,
Yes ofcourse, GMAT or GRE is necessary. You must also gain substantial years of work experience, around 2-3 years. There is no particular work experience but whatever you do must be relevant to your educational background and future goals. Most importantly you must demonstrate excellent leadership skills, managerial skills, team spirit, etc. through your work experience. You should visit the business school's website and go through the student profiles and the diverse backgrounds they come from. It is good that you are questioning and trying to build your profile from early on.

Hi Hasan Bhagat,
It depends on what you want to study and where. Exams and other requirements will vary accordingly. SAT, GRE, ACT, GMAT, IELTS, TOEFL are some common exams.

Hi Sanya, Typically, IELTS must be cleared. Most importantly you must be highly academical to be considered. You may check the university website for programme specific requirement. See here
http://www.gla.ac.uk/undergraduate/degrees/astronomy/#tab=1

Hi Adrija, chances are there that you will be able to study but you have to contact the colleges and universities directly. They will tell you what additional you have to do. Until and unless you drop an email to a university you won't get a right answer. At most they will ask you to go for a WES evaluation or ask you to do some additional courses. So please contact them. And broaden your search, look out colleges in Australia and New Zealand as well. All the best.

Hi Hariharasudan, Finland is very non conventional country choice so obviously you won't find too many consultancies dealing with Finland studies. You have to visit university websites yourself, decide what to study, take the IELTS, and follow the application process mentioned on university websites. You may also see here if you find any information
http://www.timeshighereducation.com/student/where-to-study/study-in-finland

Hi Kamal, you have to take the GMAT and IELTS to gain entry into MBA programs in UK. Majority of the MBA programs also requires applicants to have a minimum of 3 years of work experience. You can check any business school website for details.