Not only do they have the basic comfortable batik nighty to offer but they also have a variety of super comfortable kaftans & midis for the night in various prints & colours. They also offer a variety of fabrics to choose from and get your favourite styles custom made.
I picked up a Kaftan Worth ₹550/- only and got it altered into a midi kaftan which made it even more comfortable, also the alterations were done on the spot. And almost all women in my family have been picking Basic Batik A-line nighties for quite a few years now.
Give it a try whenever you are in Mumbai.