They need one more leg in SE Asia tbh. I wouldn't mind a culturally involving leg in China or even the Philippines, but tbh I agree with Claude, Indonesia wouldn't be too bad.
If they do visit India, either NE India [NE India is like what happens when you cross Bangladesh with SE Asia] or Mumbai. Mumbai would make for a chaotic city leg, but I assume they've already had a chaotic city leg in Tokyo, so I'm leaning more towards NE India.