I have set of OSM tiles in PNG format.
Now I want it to basemap or operational layers.
Can you please tell the process for same.
You can subclass ServiceImageTiledLayer like explained in the detailed description here - https://developers.arcgis.com/qt/latest/cpp/api-reference/esri-arcgisruntime-serviceimagetiledlayer....
Attached is a working example hitting the online URLs. You should be able to modify the code to point to local file URLs instead of online URLs. Make sure to update the full extent and tile info to match your tile cache.