Dear user.
Thanks for reaching out to MIUI ROM subforum.
Please note that there isn't MIUI 12.5 Beta Tester for Global ROM, there's only Mi Stable ROM Tester and this is not specifically for MIUI 12.5.
Also, Mi 9T and Mi 9T Pro are two different devices and you can be selected for one device only and you will receive test version for Mi 9T Pro only if you are selected as a Mi 9T Pro Mi Stable Tester.