As a requirement for admission to universities in Australia, international students whose native language is not English are required to take English language tests to fulfill the English proficiency requirements. Besides admission, English language tests are also necessary for visa purposes.
Since English is the medium of instruction at most Australian universities, it is believed students who demonstrate strong English language skills are more likely to succeed at their academics. Some of the most popular and widely accepted tests are IELTS, TOEFL, PTE and CAE. Some institutions may also consider equivalent test scores in other exams.
Hi Rohan- For Australia, Australian Immigration accepts number of English Proficiency Test to assess the ability of the student to check English. IELTS, PTE, TOEFL etc.
Which test is to give totally depends on the person and the situation. However IELTS is the world wide acceptable english proficiency test but student should check the university countries requirement before sitting for the exam.