Neither the film, nor either of the novelizations address this.
However, Obi-Wan planned to contact the Jedi Council after arresting Fett, so presumably they could discuss transportation at that point. Doing so prior to actually arresting him would be a wee bit premature, as the events showed.
From the film:
Yes, Master. I will report back when I have him.
From R. A. Salvatore's novelization:
“Into custody, take this Jango Fett,” Yoda instructed. “Bring him here. Question him, we will.”
“Yes, Master. I will report back when I have him.” Obi-Wan glanced over his shoulder again and abruptly instructed R4 to cut the transmission.
From Patricia C. Wrede's Disney Junior Novelization:
Important, this clone army was, certainly; but also a distraction. Yoda frowned. How to reconcile the two? “Into custody, take this Jango Fett,” he told Obi-Wan at last. “Bring him here. Question him, we will.”
“Yes, Master,” Obi-Wan said. “I will report back when I have him.”
Had he succeeded in capturing Jango, Kenobi would have contacted Yoda to discuss how to bring Jango to Coruscant. We can speculate that the Jedi would send a transport, or maybe Kenobi would use either Jango's ship or borrow a ship from the Kaminoans.