The US Student Visa is way too complicated than any other country; not just the visa process, but getting admission in good US institute is quite difficult and complex as well.
For starters,
You need to give a GRE test to apply for the admission in a decent US institute (poor Schools do not ask for GRE score, but you wouldn't get a visa with the offer letter from some 3rd class institute).
usually, Each decent institute has a level of GRE score, and they do not accept student below that score.
Scoring good in the GRE exam is too difficult as well.
After completing the GRE, you need to evaluate your Transcript using 3rd Party service.
The evaluation process is quite costly and way too time consuming, in most of the cases, you have to send your ORIGINAL Transcript to the Evaluation service provider for evaluation.
What they really do is they convert your transcript in the US system, it usually takes 1-3 months (you can pay extra $200 to $300) for urgent service.
After that the Evaluation company will return your original transcript to you and they will also courier it to your selected institute by themself (you have to pay the courier fee too).
This process is way too time consuming,
Now, after doing all this stuff (evaluation, GRE Exam, IELTS etc), you now need to find those institutes who accept GRE score less than or equal to what you have scored.
You need to apply to at least 3 schools (usually student applies at 5 to 6 schools), this is because, the US Visa officer believes that only bona fide students apply to more than one school, in case if you applied to only one school and accepted than Visa officer will reject you right away (in extreme circumstances he may accept you too).
Let's suppose you have granted the US visa and your sole purpose is to get the PR after completing your studies.
One thing to remember,
After completing your studies, you have to find a job within 3 months or else you will be deported.
How i know all that ?
My US Student visa is in process right now
and I have went through all this stuff in past 6months.