Footage on social media appeared to show fights between fans of the two clubs ahead of the second qualifying round second-leg tie at Ibrox.
Police Scotland confirmed that they had been called to Edmiston Drive at its junction with Paisley Road West just after 7pm.
In addition, the force confirmed that two men, aged 24 and 40, were found injured.
The two men were taken by ambulance to the Queen Elizabeth University Hospital for treatment for stab wounds, and medical staff have described their conditions as stable.
"This type of violent behaviour will not be tolerated and it is absolutely vital anyone with information that could assist with our investigation comes forward," Detective Inspector Steven Wallace said in a statement.
"I would appeal to anyone who was in the area and witnessed a disturbance, particularly anyone with mobile phone or dash-cam footage, to get in touch."
Rangers went on to claim a 1-1 draw against Osijek to progress to the third round with a 2-1 aggregate win.