Really? I can't find a source on this, but my impression is that this phrase was part of Victorian English and introduced to India at that time. Like many dialectical differences between English-speaking countries however, this usage continued in India even after going extinct in Britain.
Google Ngram Viewer seems to agree, putting peak usage of "do the needful" in the mid-1800s. A phrase I would tend to use instead, "do what is needed", appears to be much more recent.
Really? I can't find a source on this, but my impression is that this phrase was part of Victorian English and introduced to India at that time. Like many dialectical differences between English-speaking countries however, this usage continued in India even after going extinct in Britain.