Rajpath to India Gate, Connaught place inner circle, Central Ridge, Lutyen's Delhi would be a good option
Signature Bridge could be an interesting location!
Cp, rashtrapati bhawan, india gate
Chanakyapuri, cp,near Rashtrapati Bhavan, deer park
List of Places to Hangout in Delhi with friends
The Garden of Five Senses.
Little Theater Group Auditorium.
Indian Mountaineering Foundation.