You can never take a tax deduction for income that was never paid — you can’t subtract from something you never got.
If this was related to your business, then you might have business costs you were trying to recover. Those costs should already have been deducted as regular business expenses when they happened. Plus your attorney and court costs would be business expenses. If you were paid, that would be taxable income. The fact that you haven’t been paid means you don’t pay income tax because you don’t have the income, that’s your tax “reduction” for not being paid.
If it’s a personal situation, there’s nothing to deduct anyway in most cases, and you still can’t subtract something from your income that was never part of your income to begin with.
