You will be not disappointed with Shanghai. There you can find very good Indian restaurant. Let me recommend some Indian restaurants for you:

1)Masala Art
This restaurant provides pure English communication. It's a very nice place. Address: 3-5, Lane 418, Wuyi Road, Changning District, Shanghai (near Zhongshan Park)
2)Kaveen's Kitchen
This is a very small restautant. It's decorated in Indian style. The dishes are very tasty. Address: 2/F, 231 Huashan Road, Jing'an District, Shanghai

3)Indian Kitchen
The food is good. Many foreigners go there.
Address: 527 Yongjia Road, Xuhui District, Shanghai

There are many Indian restaurants in Shanghai. I cannot write all of them here.

You may see the following page. There are more details of the Indian restaurants in Shanghai. Hope it helps. :)

https://www.travelchinaguide.com/cityguides/shanghai/dining/indian.htm