Sky High, Scarlet, Dramz, QLA, Thai High and Limitless are some good options
Mia Bella in HKV is nice. Thai high in qutub. Dramz in Mehrauli.
There are many roof top restaurant available in rajouri garden.
Potbelly, Hauz Khas Social, Mia Bella
Dramz, located near qutub minar gives you a stunning view of historical monument and serving best food.