In case of web map, you should do it like this...
AGSPopupInfo *popupInfo = [self.webMap popupInfoForFeatureLayer:(AGSFeatureLayer*)graphic.layer];
AGSPopup *popup = [AGSPopup popupWithGraphic:graphic popupInfo:popupInfo];
popup.allowEdit = YES;
self.popupVC = [[[AGSPopupsContainerViewController alloc]initWithPopups:[NSArray arrayWithObjectopup]]autorelease];
Regards,
Nimesh