Get rego for an vehicle from interstate
If you have a vehicle that is currently registered interstate, or has expired interstate registration, you will need to register it in NSW.

You need to go to a motor registry, or send an authorised representative, to register the vehicle.

What you need to provide:

Proof of your identity, or, if you're registering the vehicle in the name of a company or organisation, proof that the company or organisation is a legal entity.
Proof of entitlement to register the vehicle.
Note: To be exempt Stamp Duty, the vehicle should be registered the same way as currently registered interstate. You must provide a current certificate of registration. If the certificate has been lost, an RTA motor registry can organise verification. (miniumum 48 hours required for verification)
Proof of your residential address in NSW.
A valid green slip with the number plate section blank (except for trailers).
A blue slip from an Authorised Unregistered Vehicle Inspection Station (AUVIS).
Evidence of repairs if the vehicle is a repairable write-off.
An engineer's certificate if the vehicle has been modified beyond the owner-certified level, or is an Individually Constructed Vehicle (ICV).
The interstate number plates.
A completed Application for Registration form, available from the Registration Forms link below.
Evidence of your eligibility for a pensioner or other concession if you intend to claim one.
A Representative's Authority if the vehicle is being registered in the name of an organisation, or if you send someone to register the vehicle for you.
For a company, the Director or an authorised delegate must complete and sign the Representative's section on the Application for Registration form, or provide a letter of authorisation on letterhead.
In the case of an incorporated association, the Public Officer must sign.
In all cases, the authorised representative must provide proof of their identity.
Payment for fees, taxes and charges.
All vehicles presented for registration (including interstate and imported vehicles) may need to be inspected by the RTA's Vehicle Identification Inspection Unit (VIIU). There is an additional fee for this inspection. If your vehicle needs a VIIU inspection, you will be notified at the time of registration.
What you need to pay:

Registration fees.
Stamp duty.
Number plate fees.
Inspection fee (the blue slip).
Vehicle identification inspection fee.
CTP insurance premium (the green slip).
You can use our Rego Calculator to work out costs for your vehicle.

This is probably a case where the RTA is not following the RTA rules.

Its NORMAL for the RTA not follow RTA rules