I am planning for a 3-week summer course with credits in the US. It was suggested to apply for an F1 visa, despite being the holder of a B1/B2 visa (travelled to the US a couple of times and never overstayed). What are the chances of getting an F1 for such short term course and the chances of having the B1/B2 cancelled if the visa response is positive or negative?
The fact that determines whether you need the student visa or can travel on a tourist visa is whether the course offers academic credit.
If the course offers credit toward an academic degree, then you must be on a student visa, no matter how short the course is.
A visitor (B) visa permits enrollment in a short recreational course of study, which is not for credit toward a degree or academic certificate. Learn more about Visitor Visas.
Study leading to a U.S. conferred degree or certificate is never permitted on a visitor (B) visa, even if it is for a short duration. For example, a student in a distance learning program that requires a period of time on the institution’s U.S. campus must obtain a student (F or M) visa prior to entering the United States.