The Mitch Rapp novels are generally numbered in the order of their publication. For example, 'Transfer of Power' was one of the early ones. However, it's best to check the official Vince Flynn website or a major book retailer's listing for the exact order as there are quite a few in the series.
The order of Mitch Rapp novels can be a bit tricky as there are many. But starting from some of the earlier ones like 'American Assassin' which gives a lot of backstory on Rapp. Then comes 'Kill Shot' and so on. You can also look at the publication dates on the books themselves or on an online bookstore to get them in the right order.
The Mitch Rapp series is quite extensive. Some of the first novels in the series include 'Transfer of Power' which sets the tone for Rapp's character and his role in the fictional world of counter - terrorism. As the series progresses, books like 'The Third Option' continue to develop Rapp's story and the complex world he operates in. Each novel builds on the previous one, so reading them in order of publication is recommended to fully understand the character's evolution and the overall plot arc.