In 6 months, you need to go from being a complete beginner in German to reaching the advanced stage. The amount of ground you need to cover is fairly bit. When you learn German, as well as any other language, you'll need to devote much farther time to the advanced stage than you would as a beginner and an intermediate pupil. How important? ideally, you'd spend, perhaps, two times studying advanced German material. But you don't have two times, you've got 6 months, and you need to start in the morning!

Source:
German Language Classes in Pune