Based on publicly available information, it's not possible to verify the existence of a specific "Russian Institute" that offers courses with Lesson 13 focused on the topic implied by the title. However, there are various educational institutions in Russia that offer courses on language, culture, and other subjects.

: Russian Institute 13: Gang Bang (2010) is one of the most cited entries in the series, often referenced in databases like IMDb due to its specific focus on group-oriented content.