create type t_type as object(empno number);
create type tab_type as table of t_type;

declare
  t1 tab_type;
begin
  select empno bulk collect into t1;
end;
/

1 declare
2  t1 tab_type;
3 begin
4  select empno bulk collect into t1 from emp;
5 end;
/

SQL> create type t_type as object(empno number);
  2  /

Type created.

SQL> create type tab_type as table of t_type;
  2  /

Type created.

SQL> declare
  2    t1 tab_type;
  3   begin
  4    select empno bulk collect into t1 from emp;
  5   end;
  6  /
  select empno bulk collect into t1 from emp;
         *
ERROR at line 4:
ORA-06550: line 4, column 10:
PL/SQL: ORA-00932: inconsistent datatypes: expected UDT got NUMBER
ORA-06550: line 4, column 3:
PL/SQL: SQL Statement ignored

        select t_type (empno)
          bulk collect into t_tab
          from emp
         where ...