Can men and women read Pancharathra agama text without undergoing samashrayanam? Is it similar to the Vedas which require one to have undergone upanayana? Not asking this learn this properly, instead wanted to know if I could read this like any other book.

It is not a practice for women themselves to read Pancharathra agama; they can learn about this from elders.
Men must not read Pancharathra agama without undergoing samashrayanam; even for reading this like any other book, one must have undergone samashrayanam.