Hi @AmalRaj and Welcome,
Whenever you create an item using QQmlComponent and create you must set it a visual parent using setParentItem. For that you will need to cast it to QQuickItem otherwise it wont be displayed
QQmlComponent component(&engine, QUrl(QStringLiteral("qrc:/Game.qml")));
QQuickItem *object = qobject_cast<QQuickItem*>(component.create());
Then try setting its properties.
P.S: The forum use markdown syntax. So while posting code surround it with ``` (3 backticks) so that it appears more readable. I have edited it this time.