I just got the reply from Ontario provincial nominee program to my earlier posted question. I had posted same question to Opportunities Ontario Program. Here is the answer:
"The English General IELTS tests four areas - listening, reading,
writing, speaking and are given a band score from 1 to 9. They are
added together and divided by 4 to get the mean. Overall band scores
are reported to the nearest whole or half band. If the average across
the four skills ends in .25, it is rounded up to the next half band, and
if it ends in .75, it is rounded up to the next whole band. If you
received an overall band score of 7, you DO NOT need to redo the IELTS
test.
SOURCE:
http://www.ielts.org/researchers/score_processing_and_reporting.aspx.