J-man had a response for every attack he got thrown at him and he basicly handled every pain and defeated them with the fact that they had way more of an advantage then nagato would because of their mobility and sight from diff angles. If jman knew where he was or if nagato would of fought him man to man i believe nagato would be defeated or in the least they would both die. Especialy if he would of fought him man to man, jman has tons of experience and wouldnt do the same stupid things naruto and bee did.
Nagato himself is more powerful than the Six Paths.
Obviously Nagato's legs are an issue, but assuming we're talking about a full strength Nagato vs a full strength Jiraiya, Nagato would win.
Nagato has complete mastery of all 5 (6) elements
If Jiraiya uses Fire, Nagato counters with Water.
If Jiraiya uses Earth, Nagato counters with Lightning.
Nagato can absorb techniques outright
This deals with any non-elemental jutsu like the Rasengan.
He can even absorb oil like when he absorbed SM Jiraiya's entire Goemon.
Nagato can summon as many animals as we wants
This easily deals with Jiraiya's summons.
Nagato can rip the souls out of anyone he touches
If Jiraiya tries to use taijutsu, Nagato will rip out his soul.
This nullifies Taijutsu.
Nagato can bring forth additional limbs from his body
Surprised attacks aren't going to be very useful against someone who can summon additional arms and use missiles and cannons. Even Bee was caught by this.
Nagato also has Deva Path's powers.
Nagato also has Naraka Path's powers.
I'm sorry, but Jiraiya cannot win against a healthy Nagato.
Nagato is more powerful than the Six Paths. His 10 second bout against Naruto and Bee proved that.