My brother (Indian nationali hailing from Kerala) is currently residing in the middle east. His F4 visa case is soon to be processed by the Chennai consular office. His DS-230 form is to be filed soon. Is it possible to change the venue of his medical exam, consular processing and interview from Chennai to the US embassy in the mid-east country where he is a resident for the past 3 years? If such a change is to be made, where and whom would he have to approach?