I need to develop an instant messaging application which incorporates the features like file transfer and content sharing (photos, videos) and enriched with all rich communication services like voice calling and group chat.
I found Orange RCS Stack library which provided well nourished API's for implementing rich communication services, but due to unavailability of services in my country (India) I suppose I am unable to use it.
If your network provider doesn't have RCS deployed, there isn't anything you can do. You'd have to implement the functions yourself, without RCS.