This is the most difficult place before an audition.
Take this problem up for solution. Think about it, develop tactics, practice them over time so they become habits that serve you.
For instance: If your fellow actors are doing a lot of chatting, you don’t need to follow suit. Just because everyone is doing it doesn’t mean you should. If it helps you to be private – be private. If your colleague asks you how you are you can say, “Let’s chat after the audition.” Have a positive pat answer to the ubiquitous question “How are you doing?”
Don’t underestimate these small efforts.
Always try and go with what you need on that day. Be particular. One day you may want to prepare quietly in the waiting room - another day you may want to chat. Go with it.
The waiting room is like the backstage in the theatre. The working space prior to performing.
Treat it as such.
Any working actor worth their salt will know you are preparing and won’t be insulted that you didn’t chat or that you did chat.
Before you go to the audition visualize the room, the casting people and what actors in your type might be there. Especially see the rooms, casting people and actors that you don’t like.
It’s best when we feel unity with our fellow actors, all together in battle, drawing succour from one another. It’s best when we go into the audition with the idea of helping them to make their TV show. It’s best when we are at one with the system and its parts.
But…some days we need to protect ourselves and hold up the hand when someone comes over to talk.