If you're a business owner, you can deduct the fees you pay lawyers, accountants, consultants, and other professionals as business expenses if you pay them for work related to your business. In general, legal fees related to your business, including rental properties, can be deductions. This is true even if you didn't win the legal case in which the legal fees were incurred. You can generally also deduct legal and professional fees related to your business in Schedule C.
However, you generally cannot deduct the legal fees you pay to acquire business assets.