This would vary extensively on the period, but at least circa 1830s- 1880s British officials going to India would have been seen as a career move, more akin to emigration than just a job post. It was advised that newcomers to the continent did literally nothing for an entire year in order to acclimatise and not contract various tropical diseases. This, coupled with the large transport times meant postings were generally for quite some time- wives were taken along with them unless they were considered particularly 'frail' and unsuitable for the heat. Bachelors and presumably some married men took on 'bibis', an Indian mistress that functioned basically as a wife but without any legal backing and probably not openly admitted. Bibis had been a feature since the British arrival in India but were originally in more of a less reputable role as camp followers and such, and I suspect the practice died out later in the 19th century.