The first step is to check the eligibility. Use this link to check your eligibility
http://www.cic.gc.ca/ctc-vac/ee-start.asp. Please note that IELTS is not the only factor that determines that you are eligible or not.
IELTS has a major role in boosting your CRS score. Use this calculator to see the impact that higher IELTS can have on your CRS score
http://www.cic.gc.ca/english/immigrate/skilled/crs-tool.asp.
In addition to IELTS, you also need to get ECA done.
In addition to the CRS score, CIC assesses federal skilled worker applications based on six selection factors.
If you score 67 points or higher (out of 100), you may qualify to immigrate to Canada as a federal skilled worker.
If you score lower than the pass mark of 67 points, the applicant will not qualify to immigrate to Canada as a federal skilled worker and the Express Entry profile would be ineligible
Check this link to know more
http://www.cic.gc.ca/english/immigrate/skilled/apply-factors.asp
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