Why wasn't Jiraiya brought back by Nagato? When Nagato used the Outer Path technique to revive the citizens of Konoha killed in the attack, why wasn't Jiraiya revived as well?

It was revealed that the original plan was for Madara to be revived with the technique, so it's not like there was a time limit or anything.
There are several reasons.


   Jiraiya's body is buried beneath the ocean depth, so even if he would be revived there, well... it wouldn't really help him. 


Outer Path probably is limited by either distance or time which has passed since death. Otherwise, the technique would have revived people from the whole world.


   the wiki says that "the individual souls are then able to leave even the crossroad between life and the afterlife". Jiraiya should probably be in the afterlife already.

 On the contrary, Kakashi was still in the path between life and afterlife when the technique brought him back.


The wiki also says that it happens because "their rejuvenated bodies [are] acting as an anchor", so looks like the body is required.