Do I have to be in my 20s to watch rated R movies
You don't have to be 20 but you have to be above 18 years old. This is the legal age recommended to watch such movies because it is also the mature age.
Rated R is for 17 and older.
You have to be 18 years old to enter a rated r movie at the movie theater OR with someone over the age of 18 like your parent or guardian.
you have to be 17 or older