Student Visa for Foreigners though Brazil embassy

Let me know of if a foreigner to get student visa of brazil(by playing tuition fee) through Brazil embassy then what you like to suggest about it?
if any private small institute provides "Admission/Acceptance Letter" then Brazil embassy will issue visa or not?or it's compulsory to have admission in Federal University??in other words whats criteria of brazil embassies to issue student visas?
Another question is that private institutes just provide classes to learn for portugese language and they don't have further undergraduate or graduate studies programmes,what you think Brazil embassy will think that applicant just want to learn portugese language for 3 or 6 months and after that what he will do ,so maybe Brazil embassy will deny his visa??
anyways share your experiences with affections..advance thanks

If a small private institute provides "Letter of Admission / Acceptance", the embassy of Brazil will issue a visa without any problem for a period of a few months and after the student arrives in Brazil he / she must do the extension according to the contract of studies for the time needed.
If it is a letter of admission issued by the Federal University or any other it will still be better because in the universities they have a program of help and accompaniment of foreign students even for the cases of health insurance and medical certificate.