As I have understand that you are looking for android and IOS devices detection policy.
In FortiOS v6.0.x, the device detection feature contains Device-based policies – Device type/category and detected devices/device groups can be defined as custom devices, and then used in device-based policies.
However after FortiOS v6.2, these functionalities have changed.
Mac-address-based policies – A new address type is introduced (Mac Address Range), which can be used in regular policies. The previous device policy feature can be achieved by manually defining MAC addresses, and then adding them to regular policy table after 6.2. For more information, see MAC Addressed-Based Policies in the FortiOS 6.2.0 New Features Guide.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.