The requirement is federated authentication between Azure Active Directory and SharePoint on-premise 2013 Web Application. The goal is to allow users to sign in on Azure Active Directory and use their identity to access the SharePoint on-premises sites.
There is an IOS Mobile App which is connected to SharePoint 2013 using Rest API uses basic authenticaion as shown below.From the mobile ios App, files are uploaded to SharePoint 2013 Document Libraries.

Also the Web Application contains SSRS Reports. How to handle permissions for these ? Is there any particular steps required for these ?