Here's why:
* Old Man and Nephew: The main characters are Hiro Hamada, a young boy, and his older brother Tadashi, who acts as a sort of older brother/father figure to Hiro.
* Robot Developing Company: The story revolves around Hiro's discovery of a robotics company called "San Fransokyo Institute of Technology," which is a fictional city inspired by San Francisco and Tokyo.
* Foreign City: The city of San Fransokyo is set in a fictionalized Asian-inspired setting.
While the specifics might not be completely identical to your recollection, Big Hero 6 seems to fit the description you provided.
Do any other details about the movie come to mind? That might help pinpoint the exact film!