Error While Calling A Procedure
When you create an object in Oracle with double quotes, Oracle creates that objects with the same case as you entered it. Try dropping the "insert_family"   procedure and creating it without the double quotes.

This should help.

SQL&gt; CREATE TABLE family
  2       ( NAME          VARCHAR2(25),
  3         NICK_NAME     VARCHAR2(15),
  4         GENDER        CHAR(1),
  5         AGE           NUMBER(3),
  6         MARITL_STATUS VARCHAR2(15),
  7         QUALIFICTN    VARCHAR2(20),
  8         NO_OF_CHLDRN  NUMBER(2) );

Table created.

SQL&gt;
SQL&gt; create or replace procedure "insert_family"
  2     ( NAME varchar2 ,
  3       NICK_NAME varchar2 ,
  4       GENDER VARCHAR2,
  5       AGE number,
  6       MARITL_STAUS varchar2,
  7       QUALIFICTN varchar2,
  8       NO_OF_CHLDRN number)
  9  is
 10  begin
 11  insert into family values(NAME,NICK_NAME,GENDER,AGE,MARITL_STAUS,QUALIFICTN,NO_OF_CHLDRN);
 12  end;
 13  /

Procedure created.

SQL&gt;
SQL&gt; create or replace procedure "Insert_family"
  2     ( NAME varchar2 ,
  3       NICK_NAME varchar2 ,
  4       GENDER VARCHAR2,
  5       AGE number,
  6       MARITL_STAUS varchar2,
  7       QUALIFICTN varchar2,
  8       NO_OF_CHLDRN number)
  9  is
 10  begin
 11  insert into family values(NAME,NICK_NAME,GENDER,AGE,MARITL_STAUS,QUALIFICTN,NO_OF_CHLDRN);
 12  end;
 13  /

Procedure created.

SQL&gt;
SQL&gt; create or replace procedure "iNsert_family"
  2     ( NAME varchar2 ,
  3       NICK_NAME varchar2 ,
  4       GENDER VARCHAR2,
  5       AGE number,
  6       MARITL_STAUS varchar2,
  7       QUALIFICTN varchar2,
  8       NO_OF_CHLDRN number)
  9  is
 10  begin
 11  insert into family values(NAME,NICK_NAME,GENDER,AGE,MARITL_STAUS,QUALIFICTN,NO_OF_CHLDRN);
 12  end;
 13  /

Procedure created.

SQL&gt;
SQL&gt; create or replace procedure "inSert_family"
  2     ( NAME varchar2 ,
  3       NICK_NAME varchar2 ,
  4       GENDER VARCHAR2,
  5       AGE number,
  6       MARITL_STAUS varchar2,
  7       QUALIFICTN varchar2,
  8       NO_OF_CHLDRN number)
  9  is
 10  begin
 11  insert into family values(NAME,NICK_NAME,GENDER,AGE,MARITL_STAUS,QUALIFICTN,NO_OF_CHLDRN);
 12  end;
 13  /

Procedure created.

SQL&gt;
SQL&gt; exec insert_family('AYUSH','SHUKLA','MALE',12,'UNMARRIED','SCHOOL',0);
BEGIN insert_family('AYUSH','SHUKLA','MALE',12,'UNMARRIED','SCHOOL',0); END;

      *
ERROR at line 1:
ORA-06550: line 1, column 7:
PLS-00201: identifier 'INSERT_FAMILY' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored


SQL&gt; select object_name, object_type, status from user_objects where upper(object_name)=upper('inSert_family') order by 1;

OBJECT_NAME                    OBJECT_TYPE          STATUS
------------------------------ -------------------- ------------
Insert_family                  PROCEDURE            VALID
iNsert_family                  PROCEDURE            VALID
inSert_family                  PROCEDURE            VALID
insert_family                  PROCEDURE            VALID

4 rows selected.