Not sure where you are applying, so this may not be applicable.

I am a piston single/some multi guy (part 91 stuff) and interviewed recently at Republic. I got the Sheppard airline prep and the questions were mostly on wx and ifr procedures, etc. and were all in the Sheppard prep (they had 20 questions you did on an iPad while they looked at your logs).

The oral was basic IFR stuff. Know your regs. Also they show you a Jepp approach plate you have to brief and get asked about. Know the Jepps (they have stuff at their website).