The Sky Bet League One club have not elaborated on the issue but 22-year-old Ranger is due to appear in court in January after being charged with rape in connection with an alleged incident in Newcastle earlier this year.
Ranger denied the charge at a hearing at Newcastle Crown Court in October.
He was given time off by the club last weekend but then failed to turn up for training on Thursday.
However, the Robins have now confirmed the former Newcastle star, who joined the club in August, will be granted extended leave.
A statement read: "Nile Ranger has been permitted time off to address his legal situation on matters publically disclosed prior to his joining the club.
"During the time Nile has been with Swindon Town, he has been a hard-working and respectful member of the squad and has respected the club's policy and supporters.
"He has given 100 per cent every time he has stepped on to the pitch in the colours of STFC.
"The club will be meeting Nile's representatives early next week to get an update on his legal situation and to review where we are in what is a difficult time for Nile and his family."