Dear Sir,
Welcome to Bonn.
we are a cultural organisation and work on volunteer basis.
We won’t be able to you finding an accommodation.
Believe it or not, we get more 2-3 requests daily.

We wish you all the best in search of a suitable accommodation. 

Looking forward seeing you one day at one of our events.

There are lots of Facebook groups, we will mention some where there rooms/ flats are offered:

housing in Bonn

Indians in Bonn

Netzwerk Bonn 

The University of Bonn offers accomodations to the Students:
https://www.uni-bonn.de/en/studying