No, there is no pre-installed Google camera on Xiaomi Poco M3 Pro 5G. The Xiaomi Poco M3 Pro has only a stock camera app like all other so many models of Xiaomi Poco.
The Xiaomi Poco M3 Pro 5G has excellent stock camera features that make the phone incredible on the mid-range entry-level budget phone. But, there is no pre-installed google camera app on the phone. But, if anybody wants to get a Google camera on the phone, just download and install the Google camera app from Google Playstore and simply enjoy the features of google camera.