Each country has its own individual eligibility requirements. Countries like Australia, Canada, U.K, and Germany follow a points-based system to assess the eligibility of applicants who wish to migrate to the country for residency, work or study. In order to meet the eligibility norms for these countries, you must score the required points. The number of points and the criteria for getting these points differ from country to country.
Before you fill the application form for any of these countries, it is better that you get an eligibility evaluation done. This will help you understand if you meet the required criteria and can score the required points. This in turn will help you assess your chances of getting the visa.