Nanjing South Station is not surrounded by a certain business district, so there aren't many food options. Here are some restaurants that might suit you:

1. Nanjing South Railway Station Food Plaza: Located inside Nanjing South Railway Station, Nanjing South Railway Station Food Plaza offers a wide variety of snacks, fast food and specialties, such as roasted duck, salt-water duck, xiaolongbao and ramen.

2. Auspicious Ruyi Catering Restaurant: Located near Nanjing South Railway Station, Auspicious Ruyi Catering Restaurant is a Chinese fast food restaurant offering a variety of rice, noodles, soups and stir-fried dishes.

3. McDonald's and KFC: There are McDonald's and KFC fast-food restaurants located in Nanjing South Railway Station, offering a variety of burgers, fries, fried chicken and other fast food.

4. South Railway Station Hotel Restaurant: South Railway Station Hotel Restaurant is a restaurant offering Chinese breakfast, lunch and dinner with a wide variety of dishes at affordable prices.

Other than that, you are advised to use food apps like Dianping to find more food options near Nanjing South Railway Station.