Pragya may have broken Alia down enough to just get out of jail. Don't know what info she'd need from Alia in exchange for her release. I don't think she would tip her hand by letting Alia know that she knows about Tanu though. Pragya would definitely be wary about Alia's motives and not trust her completely. But in order to expose Tanu she might need to see the two besties conspire together. Maybe she's bugged the outhouse with CCTV cams.
Abhi doesn't have the entire truth for him to go to Alia and have her released. He may suspect Alia behind Sarla ma's kidnapping, as revenge against Pragya, but it would have been difficult for her to do from a jail cell.
Raj is a definite possibility, as we really can't tell if he really has changed. He would definitely want Alia on his team if he was still on the dark side. Or maybe he is using Alia to expose Tanu to atone for his guilt in Bulbul's death. Maybe he thinks that Abhi would have no reason to trust him after everything and that he really does need to show proof that to show that Tanu lying about the paternity. And the best way to bring the truth out would be to use Alia.
Takhil is also a big possibility. Tanu relies on Alia's plans to get her out of trouble. She knows that Alia can make or break her chances to be with Abhi. And she would need Nikhil to post the bail to make it happen. So many things have been going wrong for her and she knows she needs Alia to help her out of this mess. Also she could shift the blame onto Alia, since Alia's already been exposed as a villian, so that she can get away free if anything were to go wrong.
I've noticed that no one thinks Purab may have gotten her released. Yeah he knows that she tried to kill Bulbul but even after the first attempt against Bulbul he prevented Alia from going to jail. Mostly for Abhi's sake, but he did save her. He may have appealed to her good side, like he has in the past to be the better person that he knows she can be. Ie.. like during the party where she was going to ruin Pragya's mama's food. Or when he wanted her help to get Abhi and Pragya together and they did the photo shoot. Alia didn't even think about Tanu because she was focused on gaining Purab's affections. I could totally see Purab using Alia's feelings about him to get Tanu's truth out in the open.
Her past associates: Corporator, Decorator (Vijay)...very low possibility but not ruling them out. Corporator would be better than Decorator only because he's got more history with the other characters. And Bulbul's death would be something that he would want to avenge. Corporator would probably have more connections to get himself and Alia out of jail. He did use the police to hold Abhi, he wasn't successful in harming him at the time because Pragya threatened to leak everything to the media. Also I loved him as the villian. Who knows maybe he's even got Bulbul.
Side note: Thai ji said something about Abhi forbidding everyone from the outhouse. Can anyone think of a reason why? It's not like it's an old family property and that the outhouse would hold memories of his parents pr something haunting. He's a self made rockstar worked his way up from nothing. Made himself what he is and bought that house for Dadi.