Opting to study in a foreign country needs you to abide to a number of rules. These rules may be in respect of your previous education or may ask for some additional courses/tests. Appearing for English language proficiency tests such as IELTS and PTE are one of those prerequisites that you may need to consider while applying for a student visa.
English language proficiency tests evaluate your English communication skills (listening, reading, writing and speaking). You can easily find the websites for PTE practice online. Although these tests increase your chances of getting a visa, you may choose not to appear for these if it is not required by the institution you are seeking admission into. However, certain institutions may opt for their own criteria to evaluate your English language proficiency. The criteria could vary from institution-to-institution or country-to-country. There are many such institutions, that don't ask for English language proficiency tests, in various countries which are among the favorite destinations of students. List of a few famous institutions in Canada, USA, UK and Australia along with their admission criteria is provided below:
1. Canada: If you have lived and attended a school, for at least four years, where English was the primary language of instruction, then you may not be required to submit a proof of language proficiency through tests such as PTE/IELTS in many Canadian institutes. Following are a few of these:
Carleton University
Concordia University
Brock University
These universities may conduct their own test or interview to test your English language abilities.
2. USA (United States of America): There is no fixed criteria, rather a number of approaches are followed by different American universities. A list of a few universities/institutions offering admission without IELTS/PTE, followed by their own admission criteria is given below:
The State University of New York, University of Arkansas, University of Dayton: Here you will have to undertake the Intensive English Language Program (IELP).
California State University: If you have attended secondary school or/and graduate school where you were taught in English, then you don't have to submit the English language proficiency test score to seek admission.
University of New Orleans: The university offers conditional admission to international students with secondary education or degrees from certain other countries.
3. UK (United Kingdom): In UK, the rules are university specific and are discussed below:
1. University of Warwick: If you want to enroll without IELTS, a programme in English for postgraduate studies (PEPS) is available.
2. The University of Bolton: If you have a score of 60% or above in 10th or 12th class in English, you may not be required to submit the proof of English language proficiency. However, you may be required to clear a telephonic interview or Skype interview.
3. The University of Bristol: Many programs in this university don’t require ILETS. But, you may be required to take a pre-sessional language course offered by the University or a different course in your home country which qualifies the requirements of the University.

4. Australia: The criteria here varies from considering the previous education to undertaking various pathways. Various universities are given below:
1. Victoria University: If you have completed a qualification where the primary language of instruction was English, then you may not be required to sit for IELTS or PTE.
2. Swinburne University of Technology: If you choose to study English at the Swinburne English Language Centre, or if you have had English as your language of instruction in your previous education, then you would not be required to submit scores of such tests.
3. The University of Adelaide: If you complete a Pre-enrolment English Program (PEP) successfully before commencing your course, you will be exempted from submitting IELTS/PTE score.
4. The University of Queensland: If you have completed a full-time course at a place, where you had English as your medium of instruction, or if you have worked in an English-speaking professional environment for a minimum of 5 years, then you are exempted from these tests.
5. The University of Southern Queensland: If you have completed high/secondary school or college with English as a medium of instruction, you may not be required to take any such tests. The University website also suggests undertaking the USQ pathway programs for admission to the university in place of English language proficiency tests.

Getting a student visa is definitely affected by your IELTS/PTE score but doesn’t completely depend on it. If the university is convinced about your English language abilities (through their own criteria) and is ready to provide you admission, granting visa would least depend on the absence/presence of such scores. And yes, you would need to convince the interviewer for visa grant about your proficiency in English.