I want to integrate with a call center application. I need to generate a rsl fil

Assuming you're using a cdt list that has a similar structure as the records in the file:

1) Create an expression rule that maps an instance of your CDT to it's text representation.
2) Use the apply() function to iterate over your list of CDTs.
3) Use joinarray() with char(10)&char(13) as your delimiter to create a single CRLF delimited string.
4) Use the Text from Template smart service to save this text into your .rsl document.

Assuming you're using a cdt list that has a similar structure as the records in the file:

1) Create an expression rule that maps an instance of your CDT to it's text representation.
2) Use the apply() function to iterate over your list of CDTs.
3) Use joinarray() with char(10)&char(13) as your delimiter to create a single CRLF delimited string.
4) Use the Text from Template smart service to save this text into your .rsl document.