1. Budget and Ultimate Goal
How much are you willing to spend on your education?
Can your parents/relatives sponsor your education or will be applying for an education loan?
Do you want to settle abroad or come back to India?
These are some of the most basic elements that you need to think about, before deciding on the country/course etc.
The UK is great for humanities-based courses, but the chances of getting a job there are close to nil. Germany is great for core engineering fields such as Mechanical or Electrical engineering. Also, the Public universities there do not have a tuition fee. You will have to learn elementary German though. The USA is superb again, for all types of courses and job prospects are fairly better than other countries. Thus, decide on your budget and career plan first. It is only after that can you have more clarity on which country to go to.
2. Field of Study
As I said, all these factors are interdependent but the priority is something you have to figure out as per your financial status. In case you do not have any financial constraints, then you can directly start researching your areas of interest and subsequently decide on a course. Also, certain countries have better prospects for respective fields as highlighted in the examples of the point above.
3. Entrance Tests and Acceptance Rate
Most post-graduate courses require a relevant entrance test. These tests may range from basic English proficiency tests like the TOEFL or IELTS to advanced aptitude tests like the GRE or GMAT. Hence, decide whether you have the time to prepare for an aptitude test or not. In case you don’t, then you will have to choose a country like Canada or Australia, which do not require an aptitude test.
Although to be able to get into top colleges, you will need an aptitude test/strong academic background no matter which country you go to.