Hi I am going to visit nanjing from 25-28 october . Can you suggest any day tour?

Well, you can visit the city as the following suggestion:
25th: After a rest in your hotel, you can pay a visit to Xuanwu Lake Park and then to Shiziqiao pedestrian street.
26th: Sun Yat-sen Mausoleum- Ming Tomb Scenic Area- Confucius Temple- Qin Huai River
27th: Presidential Palace- The Memorial Hall of The Victims in Nan Jing Massacre by Japanese Invaders- Museum- Yangtze River Bridge
28th: Xixia Mountain Scenic Area
Actually, I think there are many tours available, and you can join a local one.