Implementation of an AUTOSAR NM sequence diagram
The next step is the dotted line with function CanIf_Transmit(), the
  doubt here is it is showing as empty arguments but actually it
  contains arguments. Then why does it show as empty arguments?
  Similarly for CanNm_TxConfirmation(PduIdType, E_OK). Why is it so?
  What is the significance of dotted lines?


The diagram in your image is called a sequence diagram.

The solid line represents a method/function call and the dotted line represents the response/return for that function.

In your example, CanIf_Transmit() is just showing the return of the CanIf_Transmit(Std_ReturnType, PduIdType, const PduInfoType*) function call. There's no need to write the function parameters twice..