While the miner did not outline a specific date, it noted full production would be met early this month.
The move comes after discussions between stakeholders and KwaZulu-Natal premier Sihle Zikalala focused on securing stability and providing a stable environment for the restart. The work suspension stemmed from a rise in violence in neighbouring communities to the mine site.
Rio Tinto is contacting customers impacted by a supply force majeure that has now been lifted.
It also noted it would be reviewing the potential restart of sister project Zulti South once RBM reached operational normalisation.
"The safety and security of our people is always our first priority, and we are pleased that we will now be able to get back to work creating value for our people, our communities, South Africa and RBM's shareholders," energy and minerals chief executive Bold Baatar said.
Rio owns 74% of RBM. Titanium dioxide slag production at the site whole-year for 2019 will now likely sit at the bottom of its guidance of between 1.2 and 1.4 million tonnes.