As an older model, it seems there is only older firmware.
What version is on it?
Maybe not any older than these :
ftp:/ftp.hikvision.ru/01.%20%D0%A0%D0%B5%D0%B3%D0%B8%D1%81%D1%82%D1%80%D0%B0%D1%82%D0%BE%D1%80%D1%8B/Old%20models/DS-96128%2096256NI-E%20NVR%20128,256-channel%20Super%20NVR/