Soekarno could've remained in power if he decisively moved against Soeharto who was then Army Chief.
OTL, in March 1966, Soeharto sent units to blend in with demonstrators outside the Presidential Palace so that these units could arrest Soekarno's most loyal/left-wing ministers during a cabinet meeting. The Presidential Bodyguard caught on to this and told Soekarno. Soekarno closed the cabinet and evacuated out of Jakarta in a panic. In the chaos of the situation, Soeharto managed to gain the initiative by gaining concessions from Soekarno most significantly in the form of a letter giving Soeharto emergency powers (
https://en.wikipedia.org/wiki/Supersemar).
The POD would be Soeharto failing to take initiative, Soekarno realizing what's going on and then replacing Soeharto as Army Chief.
A surviving Soekarno regime would be dangerous. You have on the one hand the Indonesian Communist Party (PKI) sans the however many was killed in the massacres in late 65-early 66. On the other hand you'd have the Army minus Soeharto and Nasution (Another general more senior than Soeharto but who had been sidelined by this point). Soekarno's position domestically would unassailable. He'd be the only dominant political entity in Indonesia.
This is dangerous because everything would hinge on his charisma, now more than ever. Soeharto had a system. Centered around himself to be sure, but there was a system. There was a for example, a presidential line of succession under Soeharto. Soekarno doesn't even have a presidential line succession. The vice presidency had gone vacant for 9 years by the 1965-1966. It would be free-for-all when he dies.
Foreign policy-wise, Soekarno was taking a pro-Beijing position so he'd probably continue along these lines. I'm not entirely sure what'd happen with Confrontation. Economically, Indonesia would be in deep trouble. Soekarno is not an economic manager. The inflation was 594% in 1965 and Soekarno couldn't do and wouldn't do anything about it.