I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened, but congratulations on getting married.
Your father could sue the people who attacked him for his medical bills, any missed work, and pain and suffering, plus punitive damages. So could anyone else who was injured (other than the people who started it). If any part of the facility was damaged during the fight, and you had to pay to fix it, then you could sue for compensation for those amounts. If your clothes were torn, or your bride's dress ruined, you could seek the costs of repairs or cleaning. If you or your bride were injured or placed in fear of being injured, then you'd also have a cause of action for assault or battery.
However, there unfortunately isn't any cause of action that would allow you to recover the costs of your wedding reception. You're not able to get emotional distress damages unless you were part of the attacks, because the law simply doesn't allow it. When a person does something they're not supposed to do, they're liable for the foreseeable consequences of their action. You did get to use the hall up until the altercation started, so you'd never get reimbursed for what that cost. To get money back for the rest of the night, you'd have to show that it was reasonably foreseeable that guests would leave as a result of their actions - but the problem is, if 40% of your guests were still present, you were still using the hall. And it could be difficult to prove that everyone who left early would have stayed until the end had this not happened. So a judge likely wouldn't be able to award you those amounts.
If you have any questions or concerns about my response, please reply WITHOUT RATING. It's important that you are 100% satisfied with my courtesy and professionalism. Otherwise, please rate my service positively so I am paid for the time I spend answering questions. If you are on a mobile device, you may need to scroll to the right. There is no charge for follow-up questions. Thank you.