Nantah University is strong in all aspects, including science; Shanghai Jiao Tong University is strong in engineering
If you choose a school for its sake (that is, because of its reputation), then Nantah University, and if you choose a school for its major, then It's very simple, it depends on the major you want.
When choosing a city, Shanghai should be developed, with many opportunities and relatively high pressure; Nanjing is not as economical as Suzhou in the province, but after all, it is also the provincial capital and an ancient city, it also has its own characteristics, and life is more comfortable.
I am currently at Nanjing University. Nanjing has a large university town with many schools together. This is an advantage and makes communication easier. The universities in Shanghai are generally not big (the land in Shanghai is too valuable).
In fact, these two schools are on the same level. I can’t say which one is better or which one is worse. It just depends on what you like in terms of details, and you can choose according to your own preferences.
Both are good schools. You will not regret attending either one. I wish you all your dreams come true.