How can I go from Bangladesh to Nanjing University China?

You may fly from Dhaka to Kunming (about 2 hours). Then, fly to NJ (about 3 hours).

You are going to Gulou Campus, right? Take metro S1 from Lukou Airport to South Railway Station, and change to metro line 1 to Zhujiang Road Station, Exit 1. Then you can see the campus.