I want to pursue MS in Mechanical Engineering so which country I should choose from USA and Germany. And is GRE necessary for Germany.

The University of Amsterdam expects a GRE score of min 155 preferably 158 in the Quantitative Reasoning section. Along with this graduate applicant must hold a bachelor's or master's degree in the relevant discipline and submit required documents including transcripts, resume, letter of recommendation, English language requirements, statement of purpose, essay, and more.

Difficulty level of GRE exam totally depends on your knowledge. In genral, Graduate Record Examination is considered moderately difficult. It tests college level vocabulary and school level math concepts in tricky ways.

The University of Tokyo offer test option when it comes to GRE scores. This means students who wants to submit the score can submit it along with their application. As per data, 81% of students who submit GRE score get admission in the PG programs.

The University of Illinois at Urbana Champaign offer test option when it comes to GRE scores. This means students who wants to submit the score can submit it along with their application. Also, they should submit letter of reference, SOP, resume, transcripts, and English language requirements for PG admission.

GRE is not mandatory for all MS programs abroad. Many universities have made it optional or waived the requirement. Some top universities in US and Canada often still require or recommend it for admission.