The governing body will hold a vote on July 4 to determine the future of the 'newco' Ibrox club and whether to allow them to return to the top flight next season.
The situation has become increasingly complex in recent days, with the news that the club could face punishment for their use of the EBT scheme adding another twist in the tale.
Top of the agenda is determining what league Ally McCoist's side, who have been replaced by 'Club 12' in the SPL fixture list, will play in come August, with a possible demotion to the SFL still possible.
The SPL campaign is due to kick-off on August 4 – and chief exec Doncaster is confident the Rangers wrangle will be sorted sooner rather than later.
He said: "Ultimately, each club will have their own feelings on it [a newco]. The reality is that the season will start on August 4.
"At some point between now and then, clarity will emerge. But I'm not going to predict when that will be.
"There was a change in the rules which took the decision making away from the board. The clubs now have to make that decision.
"If there is the verification and documentation the board require [from the newco], then the clubs will have a decision to make on July 4."
Even if Rangers are granted permission to play in the top flight next term, the club could face severe sanctions if found guilty of using alleged 'double contracts' to pay players during Sir David Murray's reign.
The SPL's investigation has concluded there is a case to answer over EBTs – and the Ibrox side could be stripped of titles – one of 18 possible sanctions – if they are found guilty when an Independent Commission is convened under SPL disciplinary rules.
The matter is clouded by the fact the club are now a newco under Englishman Charles Green, so it's unclear if the 'oldco' or the 'newco' would take the rap.
Doncaster said: "The board will have to make a decision on who to prosecute. They are charges at the moment. They are not proven.
"The sanctions which apply to any alleged breach of our rules are absolutely unlimited.
"There are 18 different types of sanctions and there is no tariff set out. So it is a case of whatever is deemed appropriate in this case by an Independent Commission if guilt is established."
A Rangers source said: "Details of the renumeration trust were given every year and were passed by the SPL.
"They granted the licence that allowed Rangers to represent Scotland in European football.
"Are the SPL now going to sit in judgment of itself in light of this decision?"