The annual competition was initially due to start on 8 August and see the six rounds of home and away fixtures contested over the space of eight weeks, but the coronavirus pandemic caused it to be pushed back.
Now, 7 November has been slated as the start date for a six-week Rugby Championship hosted entirely in New Zealand, which Marinos revealed is near to being confirmed.
"I feel as if we're close. If numbers and infections [in New Zealand] remain at this level or start improving, then we're very optimistic," Marinos said.
"But one can't ignore the fact of what we saw in New Zealand a few weeks ago, when there was an outbreak out of nowhere and swift reaction that was taken in order to contain it.
"There is always that element of unpredictability, but my philosophy throughout this whole pandemic is you've got to control the controllables, and make sure we're doing everything we can so that when the green light is given we can turn things on.”
He added: "We certainly remain very optimistic and positive to get the Rugby Championship underway.
"We're doing everything we can within our confines, and certainly working in a very cooperative way with the New Zealand government.
"NZ Rugby have been leading a lot of those discussions. We keep plugging away."
It has been reported that reigning champion and Rugby World Cup winner South Africa, plus Australia and Argentina, could be based together in Queenstown on the South Island, with the All Blacks travelling around the country as normal.
Marinos was unwilling to confirm whether the Rugby Championship would follow the examples in other sports by creating a bio-secure bubble for teams.
"We have explored the possibility of centralising the other teams and just bringing them in and out for the various games. But again, that is very fluid. It's just a concept that we have considered," he said.
"The biggest challenge has always been that the players are going to be in a safe environment, and there is no doubt that New Zealand and Australia are probably safer than most major centres from an outbreak perspective.
"The other thing goes to player welfare. The quarantine can be managed if there is mobility and movement, and they can prepare.
"Given the stop-start nature of the seasons so far, it is imperative that players get as much physical activity as often as possible in order for them to stand up to the rigours of six Test matches in six weeks."