Maybe it's considered normal in Brazil but I think it's strange and unethical in the first place that you have to intern first for about a year before being considered for an "actual" job.
Internships are supposed to be learning experiences that take place while you are still in school/university.
That being said, I think that unless you are so rich that work is just a hobby, it's hard to justify the choice to continue being an intern above receiving an actual salary right now.
So my advice is to take the other offer.