"Chenab" is clearly a very good Indian restaurants in Berlin. I have eaten there very often (more than 30 times) and I was always at least satisfied, but also overwhelmed several times. Chenab offers an extensive selection of delicious vegetarian dishes and there is a list of dishes that can be prepared vegan online (or you can just ask the waiter). Carnivore friends told me the meat there was not the absolute top quality, but as a vegan I cannot judge and I do not want to ;).
The vegan Chapati bread, Alu Chole and Tofu Tikka are awesome!
Caution: About a year ago, the owner of this restaurant has changed. Before that, the restaurant was called "Chennai". I have never been to "Chennai", but from different sides, I've heard that there were major problems with the old owner and that the restaurant had a bad name.