Mandarin and Cantonese is Chinese, that’s why they are termed as Chinese, they are just different dialects from the same language, the writing is the same, when we visited HK from Taiwan, my wife wanted to buy some medicines, she went into a shop and they couldn’t understand what she was after, so she wrote it down and they knew straight away, funny thing was, they were surprised that she could write Chinese, but that is because she IS Chinese, just spoke a different dialect. Don’t know anything about the Indian bit, so can’t comment on that.