2018/2/20 Update
In the Japanese region I have, 20 text languages are supported and 12 commentaries can be downloaded from origin.
Text language:
العربية, Český, Dansk, Deutsch (DE), English (US), Español (ES), Español (MX), Français (FR), Italiano, 日本語, Nederlands, Norsk, Polski, Português (BR), Português (PT), Русский язык, Svenska, Türkçe, 中文(简体), 中文(繁體)
Commentary language:
2018/2/20 Update
العربية
https://drive.google.com/file/d/1l_7NRoE2AMa9y0hOkdF0bT5veCama9RR/view?usp=sharing
Português(BR)
https://drive.google.com/file/d/1bva_TNBmKHdk-SxhOX-JoNUDIVL4W2Bl/view?usp=sharing
Deutsch(DE)
https://drive.google.com/file/d/1eY3Wao0ookJWcG6qDno6ZTq_ZmKwKXQ1/view?usp=sharing
English(US)
https://drive.google.com/file/d/18tinvClcT2uLN39WjQqpanAx56XlN63W/view?usp=sharing
Español(ES)
https://drive.google.com/file/d/1zey_Z37IY4Wm3KaKbLoX6qjauiautt5d/view?usp=sharing
Français(FR)
https://drive.google.com/file/d/1JwQc5HEUVRDJUcl2_t6BXKaEJqOCQyb8/view?usp=sharing
Italiano(IT)
https://drive.google.com/file/d/1fpZmh-fQ4vVA0ndHlH7vPM0A_FtW4NQB/view?usp=sharing
Japanese(JA)
https://drive.google.com/file/d/1iCjPPs04_tfUoUNLhcedM7-XslpXLfFb/view?usp=sharing
Español(MX)
https://drive.google.com/file/d/1TSB4AKzFVIYtsBO29tiqeug8DYYDgoVU/view?usp=sharing
Nederlands(NL)
https://drive.google.com/file/d/1oNLjmW7_gyy8Y7-EDgoYqtiFWlrsHH5X/view?usp=sharing
Polski(PL)
https://drive.google.com/file/d/1q2CUHhnlnLJtvACFDaOYa31RMX-iYJMY/view?usp=sharing
Russian(RU)
https://drive.google.com/file/d/1cOZHOCI-n5Yxp7GoueetCllicexmInwl/view?usp=sharing
Perhaps, the global (Europe?) Region seems to contain DB files of all text languages.
To use an unsupported text language, you need to edit FIFA 18. exe with the Hex editor.
Also, to use an unsupported commentary language, enable that text language and place a commentary language file.