Ng, who has supported the bankrupt Scottish club since boyhood, withdrew his £20 million (US$32 million) offer last month in frustration at the bidding process.
But the Hougang United chairman is now back in the race after the preferred bidder, US tow-truck magnate Bill Miller, pulled out over concerns about the club's financial position and anti-American vitriol from fans.
"It is really crazy," Ng told Singapore's Today newspaper. "There were something like 20 missed calls from Scotland on my phone when I woke up.
"I am now told they are willing to accept 50 percent of what I had initially offered. It seems they are now more receptive and no longer digging in their heels with unrealistic demands."
British reports say Ng is now competing with two British-based consortiums for the 54-time Scottish champions, who were taken to court over a £9m tax bill and then docked 10 points for entering administration.
Rangers were also slapped with a 12-month transfer embargo and fined £160,000, while controversial former owner Craig Whyte was fined and banned for life from Scottish football.
According to the administrators, Rangers' total debt could amount to £134m, with the venerable club awaiting the outcome of a tax tribunal case that could cost them £75m.
In announcing his withdrawal, Miller said he had received the message, "Yank go home!" from Rangers fans. But Ng said he had no concerns about getting similar treatment.
"I've been getting positive feedback from fans there, who know that I'm a lifelong Rangers supporter and have the club's best interests at heart," he told the Straits Times.