There is no band specification as acceptable or not. What you need is to score points to cross or meet 67 mark.
Andy Here is how you get max points
Listening 7.5 -- 4 points
Reading 6.5 - 4 points
Writing 6.5 - 4 Points
Speaking - 6.5 - 4 points
Please read page 10 of the Instruction guide for IELTS scoring
http://www.cic.gc.ca/english/pdf/kits/guides/EG7.pdf
I recommend you to read the instruction guide care fully for your application process, it will be of great help.