Germany

Germany is good for businesses management but not so good that you should go their leaving your country to study. You should rather look for some other option.

Dear Nithees,
It'll definitely be good, but you have to learn German language there and enrol in a school for 1 year.

Give GRE and apply in the university as soon as possible.

No, you just need to score good in Bachelors and German proficiency is required.

Yes, you can give IELTS only. Almost all the universities in Germany ask for IELTS. It is European based and TOEFL is American based.

You should go for Poland.

Germany is a technology advance country with lots of high technology industries. If you do MS in Germany, you have high probability to get a good job in Germany.

Hi Amal, for a better answer, you have to share what you want to study with your education background.

Hi Bharat, the term 'best' itself differs from person to person. There would be certain areas where you excel and vice versa. Figure out your interests and decide. Also, check the labor shortage list. Germany on the whole is a hub for mechanical engineers. Check this for all the information you are asking for:
https://www.study-in.de/en/