I just watched the recent episode (391) and just prior to Obito being taken over by Black Zetsu, he seemed to have acknowledged his sins and was planning on using Rinne Rebirth - but for whom? It certainly wasn't for Madara because Black Zetsu wouldn't have gotten involved. Jiraya was on his mind, so was it him? Or was he planning on reviving all of the ninja who died during the war?
Obito was trying to revive all the people he killed in battle, the way same way as Nagato did.From here
Obito attempts to amend his mistakes by using the Samsara of Heavenly Life Technique to revive those he killed, noting he had finally understand why Nagato betrayed him.
For your question why Nagato didn't revive Jiraiya... My guess is the dead people will be revived from where their dead body is,
Since Jiraiya's body was far too deep in ocean that even Kabuto can't reach to collect his DNA, it would be waste to revive him. Even after reviving he will die because of water pressure. So Nagato didn't try to revive Jiraiya.
It is also mentioned in Jiraiya's wikia page
Later on, Kabuto revealed that he attempted to retrieve Jiraiya's body to bring him back through Summoning: Impure World Reincarnation, but it was far too deep in the ocean for him to reach without being crushed by the water pressure.