IELTS is a qualification popularly used to assess whether non-native English speakers are able to take a study course delivered in English. An IELTS score of 6.0 is often taken as the level which the student has to attain before studying in English.
I have been looking into exactly what an IELTS score of 6.0 means:
IELTS consists of different parts (listening, reading, writing, speaking).
The parts are marked on a scale of 1 to 9 (higher is better)
The average of the parts is the IELTS overall score for an individual
The use of an average means that it is possible for a student to fail, say, the reading part (or any of the other parts) but still attain the 6.0 grade. However, my experience is that someone who cannot read English is probably not suited to studying in English.
The IELTS describe the 6.0 band as follows: "Competent user: Has generally effective command of the language despite some inaccuracies, inappropriacies and misunderstandings. Can use and understand fairly complex language, particularly in familiar situations."
Clearly this description does not match a student who has attained 6.0, but cannot read English at all.
An article on the web, discussing the situation in Australia, is here: http://www.crikey.com.au/2011/07/26/ielts-study-unis-failing-foreign-students-with-one-size-fits-all-approach/. However, this doesn't make clear that someone can attain an IELTS score of 6.0 without being able to read (or speak, or write) English at all.
In conclusion, an IELTS score of 6.0 overall is probably not sufficient to decide whether a student should pursue academic study delivered in the English language.