There are no offshore companies in Nevada, meaning same "offshore" companies like in tax haven jurisdictions. However if you mean to get a low or no tax company you can incorporate it in Nevada and organize your business with no tax liabilities. You should be a nonresident alien. Some people call it "an offshore company". The company is not supposed to receive any income from US sources, but it depends.
If you take offshore to mean a company not located in your home country, by all means, you can incorporate one in the state of Nevada. However, don't expect not to have any tax liabilities. Companies incorporated under US laws pay taxes in the United States.