Create table Table1
(
constraint table1_col12_pk primary key (col1, col2),
ad varchar2(10),
col1 number,
col2 varchar2(20)
);


Create table Table2
(
t_date date,
col2 varchar2(20)
constraint table2_col2_fk references table1(?????)
);

You have 2 choices:

1. Add another column "col1 number" into Table2 and "CONSTRAINT table2_col1_col2_fk FOREIGN KEY (col1, col2) REFERENCES table1"
2. Change the primary key of table1 to "col2" only.

Anyway, the combination of foreign key must be exactly same as the primary key.