Do I need to prepare for GRE or GMAT if I want to study Master of Computer Science in Germany/Singapore?

You can skip the GMAT entirely, since it is designed for business and management degrees, not computer science. Whether you need the GRE depends heavily on your target country. Singapore's top universities almost always require it, while Germany's requirement depends on which specific university you choose.

Which Exam You Need, by Destination

What to Focus On Once You Know Your Target

• Singapore: NUS and NTU strictly require GRE scores for foreign applicants; aim for a total of 320+ with a near perfect 165+ Quantitative score
• Germany's TU9 schools like TUM and RWTH Aachen strictly require the GRE for non-EU applicants, with an unofficial Quantitative cutoff around 164+
• Other strong German public universities, like University of Stuttgart, TU Berlin, or FAU Erlangen-Nurnberg, often skip the GRE and focus on your undergraduate CGPA
• Both countries still require English proficiency, typically IELTS 6.5+ or an equivalent TOEFL score

My Advice

Shortlist your target universities before you start studying, since that single decision tells you whether you need the GRE at all. If NUS, NTU, TUM, or RWTH Aachen are on your list, focus your prep almost entirely on the Quantitative section, because these programs care far more about your math score than your Verbal score.