As far as we are aware 12345 and 123456 were the only default passwords that Hikvision ever used, but most NVRs now running the latest firmware require a unique password to be entered after factory reset to activate the device. If both those default passwords don't work then you will need to do a password reset and send the reset file to the supplier you purchased the NVR from.
(If you open SADP and the NVR is showing as inactive then that means you will need to enter a unique password to activate the NVR)