If my devices lost
In my disaster scenario, my Acronis 12,5 backup server (Server 2016) is corrupt (my backed up "devices" lost also). Can I reinstall Acronis 12,5 to new server and restore my backups from my NAS device or should I use Acronis media.
both variants are possible: you can either use Acronis Bootable Media to restore your server from backups stored to NAS or install Acronis Backup 12.5 on a new server and then restore your backups from NAS. Please note that an additional reboot of a new server after it's restoration from a backup will be required in the second case.