is it possible to insert the duplicate values into a primary key column?

What you are talking about in your question is called FOREIGN KEY[^]

You cannot insert duplicate values in a primary key column. Primary key columns are unique.

Lets see how foreign key works. You usually create foreign key column in a table when the tables have 1-m relationship. Consider Employee-Department scenario. 1 department can have many employees. So you create foreign key DepartmentId (primary key from Department table) in employees table.
Now to answer your question, yes this column may have duplicate/repeated values because the there could be more than 1 employee in a department.

I hope that clears your doubt.