IELTS

As per your graduation score, you have to appear for GRE. GRE is not mandatory for Canadian universities, but it is a profile booster.

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

IELTS or TOEFL both are considered equally by most of the colleges. What you need to see is in which pattern you can score better so take a look at their details or take a mock test and see what suits you best.

IELTS is easier than TOEFL and IELTS band is accepted by all the universities.

I think you should apply for MS in USA because it is better than Germany for all the fields.

Hello Aman,
IELTS is the high stakes English test for study, migration or work.
For more you can go on:
www.ielts.org
The TOEFL test is the most widely respected English language test in the world, recognized by more than 9,000 colleges, universities and agencies in more than 130 countries, including Australia, Canada, the U.K. and the United States. Wherever, you want to study, the TOEFL test can help you get there.
For TOEFL, you can visit:
https://www.ets.org/toefl

You may start preparing it now and strengthen all your basic concepts as now a days mock tests are available on net. That will give you an idea about how much more preparation or coaching is required. Since, scores for GRE are valid up to 5 years and TOEFL 2 years, you can take tests in the final year.

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.

Both the countries have a great prospect for mechanical and automobile engineering. Germany is good for Civil Engineering where as Canada is good for Gas & Petroleum engineering, but in Germany, German language proficiency is also important.