Of course India and China are politically completely different countries and where you would be completely accepted in India speaking English, in China it will greatly be appreciated if you speak their language. In my experience English communication works OK with China nowadays but the culture is so different that to truly understand them you would also have to dive into their language. Most people I heard of going to China have learned Mandarin. It is quite a time investment but the learning curve with Chinese is quite steep I experienced. I am going to Japan in a few weeks, I am very curious how the relationship with English speaking foreigners is there.