German

1.University of mathematics

2.European school of management 

3.HHL leipzig graduate school of management 

4.Otto Beisheim school of management 

5.ESCP school of bussiness 

6.TUM school of management 

7.University of cologne

8.Frankfurt school of finance.

9.Berlin school of economics and law

10.ESB rutlingen

I don't know about improvement exam but for JEE mains:-
Unlike India, Germany has 13 years of school education and having qualified JEE Mains means, you are qualified to take admission in German universites but if you are like me who is not from IB/Cambridge and didn't qualify JEE then to study in Germany either you have to do studienkolleg in germany or complete 1year of bachelors 

The fee structure for Certificate In Russian in Acharya Narendra Dev college is like  

The passing criteria for Certificate in German Language at Acharya Narendra Dev College, University of Delhi is that you have to score minimum marks 40% aggregate in an Examination. Basic education graduates are eligible to apply for admission to this college. Students must first verify the cut-off for admissions on the DU or the college website before applying for admission to Acharya Narendra Dev College.