In film and TV auditions you will likely discuss the project as a whole, the character and the scene you are to read. Listen to the director/CD to pick up on any character hints you may not of thought of that you can incorporate. If you have rehearsed an angry scene shouting and they say it occurs in the library, you may want to adjust your delivery accordingly or ask if the character delivers in more of a controlled anger or just looses it despite being in the library (relevant questions that show you are listening are fine).
Often you will be sat with someone from the casting/ production team reading in the other roles with you. This can be tricky, as, often, they are not actors and won’t give you much to play off. Most of the time you will be acting with the top of their head as they read from the page awkwardly. The best tip is to fully prepare to imagine what the other roles would be doing, not just your own character. That way if you do have a difficult read in, you can use your preparation to imagine they are doing what you need to make sure you give the performance you want. It is about you, not them, so you need to make sure you react in a way that works for the scene, despite what they are doing.