Declare a Record Constant with a Qualified Expression

DECLARE 
  TYPE My_Rec IS RECORD (a NUMBER, b NUMBER); 
  r CONSTANT My_Rec := My_Rec(0,1); 
BEGIN 
  DBMS_OUTPUT.PUT_LINE('r.a = ' || r.a); 
  DBMS_OUTPUT.PUT_LINE('r.b = ' || r.b); 
END; 

Declare a Record Constants using a Function

CREATE OR REPLACE PACKAGE My_Types AUTHID CURRENT_USER IS  
  TYPE My_Rec IS RECORD (a NUMBER, b NUMBER);  
  FUNCTION Init_My_Rec RETURN My_Rec;  
END My_Types; 

Create a function that populates the record with its initial value

CREATE OR REPLACE PACKAGE BODY My_Types IS  
  FUNCTION Init_My_Rec RETURN My_Rec IS  
    Rec My_Rec;  
  BEGIN  
    Rec.a := 0;  
    Rec.b := 1;  
    RETURN Rec;  
  END Init_My_Rec;  
END My_Types; 

Invoke the function in the constant declaration

DECLARE  
  r CONSTANT My_Types.My_Rec := My_Types.Init_My_Rec();  
BEGIN  
  DBMS_OUTPUT.PUT_LINE('r.a = ' || r.a);  
  DBMS_OUTPUT.PUT_LINE('r.b = ' || r.b);  
END;