Hello Monish, 

In order to apply for a post graduate course in RWTH Achen university, you do not require a GATE score. 

The general admission requirements for all PG programs are:

1. An initial university degree and official transcripts for the same. 

2. German language proficiency certification: This includes the TestDaF, Goethe - Zertifikat or the CEFR: Deutche.

3. English language proficiency certification: This can include either the IELTS or the TOEFL examination scores. 

Hi Monish!This is Neeraj Atluri.In my view no university in foreign will accept gate as their entrance , they will go with IELTS and GRE.In Germany, most of the universities choose IELTS as their entrance exam and your engineering percentage .If you have any doubts regarding this reply me,I will help you.