Duff and Phelps believe Rangers could be out of administration by the end of the season after four bids were received for the stricken Scottish champions.
The administrators set a deadline of 5pm on Wednesday for "best and final" bids to be submitted for the Ibrox club.
Joint administrator David Whitehouse said: "The bids are structured in various ways but I would describe them as positive and constructive. It will be our intention to accept an offer next week... at this stage we cannot be precise in time-scale, but estimate that an exit from administration before the end of the season is achievable."
The Blue Knights consortium - headed by former Ibrox director Paul Murray - and Ticketus confirmed they had tabled an offer, while Press Association Sport understands the other bids are from groups in Singapore, Germany and the United States.
The bid from Germany is the most surprising development as there had been no suggestion of interest from the continent until now.
The Blue Knights are the only group so far to offer information on their proposal, which opposes liquidation and favours a scenario whereby Rangers exit administration via a Company Voluntary Arrangement (CVA).
Murray said: "We are determined to try and save the club in its current form. We strongly believe that there is value to be gained from the financial and football benefits that a CVA can deliver that would be immediately lost if the club went into liquidation.
"As a Rangers fan first and foremost, I want to bring a swift end to the current uncertainties that are clouding the club. Our bid can deliver this."
Whitehouse said: "The administration team will now analyse these bids over the forthcoming days and hold discussions with relevant parties to gain further understanding of the details of their bids."
Sale Sharks owner Brian Kennedy had said he would not submit a revised bid ahead of the deadline, but would return to the table at a later date if he believed the Scottish champions were in danger of being liquidated.