If that happens, you have a few options. First, you can simply take what they offer. The next step is usually to go to mediation.
Mediation involves meeting with insurance company representatives in front of a mediator. Your attorney is present, as well. The mediator will listen to each side and try to get you to reach an agreement.
If mediation works out, you might get the full compensation you need and avoid a trial. But if things don't go well, you may need to take the case to a jury. Your attorney will give their best advice if they think you can get more by going to trial.