"FR" means "File Run" and "RI", "Run during Installation". Just take care that all rsc, aif, mbm files are already installed before starting an APP(i.e. just install the App as the end of your pkg file).
Exemple:
"\Symbian\6.1\Series60\Epoc32\release\thumb\urel\MyApp.rsc" -"!:\system\apps\MyApp\MyApp.rsc"
"\Symbian\6.1\Series60\Epoc32\release\thumb\urel\MyApp_caption.rsc" -"!:\system\apps\MyApp\MyApp_caption.rsc"
"\Symbian\6.1\Series60\Epoc32\release\thumb\urel\MyApp.aif" -"!:\system\apps\MyApp\MyApp.aif"
"\Symbian\6.1\Series60\Epoc32\release\thumb\urel\MyApp.app" -"!:\system\apps\MyApp\MyApp.app",FR,RI