Getting to Shanghai take two hours through hyper-rail and Nagasaki is an hour and a half. Lotus City is currently Lotus' primary HQ with their secondary and main office in Beijing. Delta Engineering is based out of Detroit. Tokyo Robotics is, of course, in Tokyo. ArcNet, however, is one of the harder ones to pinpoint. ArcNet is believed to have started in Russia but there are conflicting reports of their HQ being in Germany or France as well. Tokyo Robotics has very few offices around the world, most of which are in the US and China. Delta Engineering is widespread and in nearly every country around the world. Lotus is similar in that aspect. The most prevalent of the companies, of course, is ArcNet who is well known to have offices spread across the world to provide their services to the masses. 

As for their presence in Lotus City, Tokyo Robotics is the only Corp without an office or any influence over the city.