Step-up basis when the owner dies is generally the market value on the date of death This becomes your tax basis that is split among the heirs based on the ownership %'s
Your gain would be your share of the selling price, less selling expenses (converted to US $), less your tax basis converted to US $, but at the historical conversion rate on the date of death.
You may have to report this in the foreign country and pay that country's income taxes on the sale. If you do, you can take a deduction or credit for the foreign taxes paid. Inherited property gets long-term capital gain/loss treatment on your US income tax return
For US income tax purposes, Form 8949 and Schedule D. For the foreign taxes, if any, schedule A if deducted or Form 1116 if you take the credit (usually best). In addition, if you have a state income tax, you may have to pay state taxes on the gain. Every state with an income tax has its own rules.
