Amazing, so you got that audition for the cool band that are looking for a new drummer/guitarist/cowbell specialist/whatever! Good job! You're half way there - but this is the tough part. Auditions can be brutally hard, and stressful. Don't lose all confidence yet though! There are ways of helping lessen the load on your head. Here's a few things that have helped me in the past.
1. Get to know the band. It is so so important to do your research about the band you have just scored an auditioned for. Learn about their history, their previous works and really what they identify as, then play this to your advantage. All this stuff is great conversation to show your genuine interest in the group. It also is a nice icebreaker - a likeable personality can massively affect your outcome of the audition - even if you played perfectly! I've found that playing alone isn't enough, you have to show that you are fun and easy to work with (but also present yourself as a professional!)
2. Learn the songs!! For the audition, you're probably going to be asked to learn a bunch of songs. This may be a little obvious, but ACTUALLY LEARN THEM. Don't think you'll be able to jam them - maybe you can, but that won't look good at all. Learning the songs properly shows a few different things: It shows you're capable of playing to their desired level, it shows you've put effort in and it tells the band that you are a hard worker. Cannot stress this point enough, You'd think it was common sense, but I once attended an audition and I was the only dude who had listened and learned the songs!
3. Bring your own stuff. This one's a no brainer. Firstly, using your own gear gives you some well-needed comfort in a fairly stressful situation. Having gear you know will work helps you focus on the music you're making - rather than stressing about how the unfamiliar bass drum pedal is too unresponsive etc... Secondly, it looks good on you if you come prepared like that. It shows you have put in that bit of effort to bring some extra gear to help you. Obviously, you have to be reasonably realistic. Don't bring a whole drum kit for a 30 minute audition!
4. Get involved! Really just get involved with the music and the band. Don't think you're playing FOR them - but WITH them. When you think this way, it can help you relax, and if you're relaxed the band are more likely to get on with you. As I said earlier, personality is a huge factor! Also, perhaps you can also message the band/manager etc, prior to the audition to: a) Refresh their memory of you, and b) find out some extra info that could give you the edge to a successful audition. Don't forget to look like you're having fun! (duh) It's a bit cheesy, but music is meant to be fun - never lose sight of that.
5. THANK THE BAND. This one is also a no-brainer, but sometimes the adrenaline kicks in and you forget how to...er be a functioning human. Thanking the band for their time if you're not successful is a huge plus especially. They'll most likely remember that, and perhaps in the future, you'll get a call offering a place (providing you weren't absolutely garbage in your audition) - you honestly can never tell.
That concludes my short list of things that can help you with your band audition. I hope you can take something from this advice. All the best in you future auditions!