Responsible Practical Training Act of 2021 This bill imposes limits on the Optional Practical Training program and addresses related issues. (The program provides an F-1 student visa holder temporary employment authorization before or after completion of the student's studies, or both. Currently, an eligible alien may receive up to 12 months of employment authorization under the program, with a 24-month extension available to certain individuals with degrees in certain fields related to science, technology, engineering, or math.) Specifically, the bill requires the Department of Homeland Security to issue regulations to (1) limit the program to six months and eliminate any extensions; and (2) exclude from the program any alien with a degree or working in a sensitive field, such as military-related fields. The Department of Labor must conduct a wage analysis of the Optional Practical Training program and Curricular Practical Training program. The analysis must include a determination as to whether the aliens in the programs received wages appropriate for the type and location of employment.