When Sasuke fully mastered the Mangekyou Sharingan during/after the Danzo fight is when I'd be comfortable putting him > Jiraiya's level by a smidgen. His offensive power would be too much for Jiraiya, his Susano'o Arrows likely too fast for Jiraiya to dodge at medium/short range, and Susano'o a barrier to almost any attacks from Jiraiya.
The toad song is what'll pose the biggest threat to Sasuke but IMO with knowledge, that jutsu relies heavily on the environment to get off. Especially on Sasuke who has a tendency to spam Amaterasu. 6/10 times, I'd favor MS Sasuke. Partially due to his aggressive tendencies like I said above, he's the type of fighter that would continuously pressure Jiraiya with Enton and Amaterasu.
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Just for the sake of spitting it out there, here's how I think the other versions of Sasuke will do.
Hebi Sasuke โ> Pushes Jiraiya to Sage Mode but ultimately loses. Jiraiya's AP here is too much for a watered down senjutsu user to endure. 8/10 for Jiraiya
Early MS Sasuke (Bee Fight) โ> Jiraiya's biggest danger is Amaterasu but honestly, he's probably KO'ing Sasuke in base before that comes out. This is the weakest version of Sasuke in Shippuden. 10/10 for Jiraiya
FKS Sasuke โ> He's almost at mature MS levels but he seems to be taking too much whiplash against the Kage from constant usage, whereas against Danzo he was more accustom to it and had higher levels of Susano'o. Sasuke has a chance if he gets lucky but I think this relies more on Jiraiya making a mistake than Sasuke's skills. 6.5/10 for Jiraiya
EMS Sasuke โ> Lol Jiraiya gets stomped on. Even if it's Kabuto fight Sasuke, his ability to spam MS jutsu without a care puts him on a tier above Jiraiya. Add in Perfect Susano'o and the fact he was adjusting to Juubito's speed (further evolution) later in the arc, and it's a 10/10.