Download
CM2MT2 v2.00 r4 and retry booting / identify operation.
I found stock rom , you can download it here:
Gionee_S10_T2089_MT6757_23062017
Be careful about flashing. If phone is booting, and can enter recovery,
it's more safe to update it via sdcard. SDCard update can be downloaded from
HERE
p.s. If, for some reason, you still cant boot that phone,
you can try with
DA Files + Auth + Preloader files
Test and post results. Don't rush into flashing the phone.
Make all possible backups (full rom backup, nvram, nvdata, etc.)
Phone can also have hardware issues. Best line is to try sdcard update first.
If customer agrees that phone may not power on after flashing,
then proceed with rom flashing via cable.
b.r.
Alex