New Delhi station premises is cleaner than many stations no doubt. If I have to say about the best zone whose all stations and trains are well maintained then it will be SCR. I have clicked a pic in the stairs of the pay and use toilet at BZA. So you can imagine how clean they are. The dirtiest station I saw is DLI. There is a huge difference between DLI and NDLS. IMO INDB se zyada Acha HYB/SC/KCG Hain. But opinions vary . I may be wrong but to me SOUTH CENTRAL RAILWAYS is the cleanest in all terms from Station to trains.