Hi Santiago,

That won't be a problem. You have to book an appointment with an NCT centre within seven days of the car arriving in the country, but that's only for a VRT inspection. You'll need to bring the car and all its paperwork along to that for scrutiny. The NCTS will then scan it all in and pass the information to Revenue to confirm to you the VRT due (it's a flat rate for classic cars of course). On payment of that you'll get your registration number, but only after that could you possibly book it in for an actual NCT. If the car is not ready for that, and you'll be garaging it and restoring it, then I'd suggest you declare the car as off the road to avoid owing motor tax as well. 

A point to note: if the car in question is over 40 years old then it does not require an NCT unless you're using it for commercial reasons.