The base game allows 4-4-2 or 4-3-3. The DB Editor accesses the formations table.
The file is opened on a PC (or sometimes via Android-based SQLite editors). Popular tools include DB Master or specialized mobile-centric DB editors created by the community. db editor fifa 16 mobile
There are specific community tutorials for converting a PC database ( The base game allows 4-4-2 or 4-3-3