IELTS Scores

If you apply in USA universities, then you have to appear for GRE with TOEFL. For other countries, you don't need to appear for GRE, only TOEFL or IELTS is enough. But if, your academic record is not up to the mark, your GRE marks help you to get admission there.
For MBA admission you need to appear for GMAT with TOEFL or IELTS as GMAT is must for MBA in abroad.
All the best.

Hi Dilpreet,
6.5 is considered good enough by most universities and programs. Many universities require a minimum of 7. Check the score explanation below to have a better understanding
http://takeielts.britishcouncil.org/find-out-about-results/understand-your-ielts-scores

Yes, your IELTS score is good. You can get the student visa of Canada.
All the best

You can only get admission in a Canadian university to pursue MS after you clear your backlogs.

No, IELTS score is only valid for two years. You need to take the test again after two years.

If you score well in IELTS and GRE , you have chances, but it's tough to get admission ,most of the applicants have good marks ,they need 75% mainly ,try to search more safer universities in Canada, like Newfoundland, York, Victoria, Laval, etc.

You need to score more than 6.5 band in IELTS to pursue BE in ME in an average Australian university.

All the universities in Canada accept IELTS score. you don't need to worry about it.
For civil engineering, you can choose any of the following:
McGill University
University of British Columbia
University of Alberta
University of Toronto
University of Windsor
University of Ottawa etc.

You can apply in Singapore, Australia, Germany, France and UAE.