It's a Chinese brand and the company has offices in Europe, so you can expect to see OPPO smartphones appear in the region.
OPPO is a subsidiary of BBK Electronics, which is one of China's largest consumer electronics companies. BBK Electronics was formed in 2001 through the merger of three companies: Skyworth, Konka Group and TCL Corporation (which also owns Alcatel).
The company plays an important role in helping India overtake the United States as the world's second-largest smartphone market. It was one of the first brands to launch a device in India that had 4G LTE connectivity, which means it could be used on high-speed networks that were only just being rolled out at the time. And it continues to be one of India's best sellers because of its products' affordability and its focus on localisation — including Indian language support for its devices.
It makes sense for OPPO to target Europe with its devices too given that it already has an established presence there — although we don't know much about its plans for this region yet