There are quite a few shops in Bonn where you can buy Indian stuff. You get a better variety in Köln and it hardly takes 25 minutes reach there.
SES IMPEX GMBH & CO KG
53175 Bonn You can buy fresh vegetables, non Veg. , fresh Naans, fresh bread, fish and various Asian stuff.
Asian Afro Shop
Johannes Strasse 34
And may more.
Ihn. Herr Babu Lal Arenja
And many more shops near Fleichmengergasse. You can call it
“Indian Chota Bazar”.