I want to create my own symbols and use/Render on MapView...Is it possible...How to Do it?
You can do this with Graphics. We have a few samples for it in our sample repo. Here is one of them arcgis-runtime-samples-qt/ArcGISRuntimeSDKQt_CppSamples/DisplayInformation/GOSymbols at master · Esr...
How to add new symbol??
You can create a PictureMarkerSymbol using a QImage and make SimpleRenderer with that symbol. QImages are capable of loading from a file(such as a .png or .jpg). To add them to the map, use a GraphicsOverlay.