The event is into the second year of a five-year contract between the NRL, promoters Duco Events and Auckland Council's events arm that ends in 2018.
Auckland Tourism, Events and Economic Development (Ateed) chief executive Brett O'Riley and Duco director David Higgins yesterday said the contract would come up for renewal within a year or so.
Mr Higgins said: "All options are on the table, really, and ultimately the NRL will do what it believes is in its best interests.
"That could be sitting down with Auckland and renewing it, it could be looking at other options, it could be maximising the value of it with a competitive process. It's wide open.
"The event is working really well in Auckland - it's a 10-out-of-10 outcome. If it's true these other cities are interested, I think that's flattering and a credit to the NRL and Ateed and everyone involved.
"The first step is that the NRL will signal its thinking - that might be first right of refusal, it might be looking at other options, whatever," Mr Higgins said.
Mr O'Riley said it was a competitive world and it would be naive to think someone else would not put up their hand up to stage the event.
This year, it would include the NRL launching its season for the first time in New Zealand, at Shed 10 on Queens Wharf with Warriors halfback Shaun Johnson as a face of the game.
The inaugural Nines event was worth $9.35 million to the Auckland economy, nearly three times the original forecast of $3.8 million. It resulted in 68,380 visitor nights, including 27,749 international visitors.
Auckland ratepayers are contributing $12 million over five years.
Cities battle for NRL Nines
*Auckland has five-year contract for Nines until 2018.
*Melbourne and Brisbane eyeing success of first event.
*Contract up for renewal next year.
*NRL to decide whether event stays in Auckland to or invite other cities to bid.
For more coverage: Keep your hands off, Australia