Trace The Value In A Table

i have 3 tables

T1
node_id

T2
node_id, object_type

T3
node_id, object_type

my requirement is T1 node_id exists in which table(T2 or T3). If T1 node_id exists in T2 then return T2 object_type else return T3 object_type

sample data
==========
create table T1
(
node_id number(4)
);

create table T2
(
node_id number(4),
object_type varchar2(15)
);

create table T3
(
node_id number(4),
object_type varchar2(15)
);

begin
insert into T1 values(10);
insert into T1 values(20);
insert into T1 values(30);
insert into T1 values(40);
insert into T1 values(50);
insert into T1 values(60);
insert into T1 values(70);
insert into T1 values(80);

insert into T2 values(10, 'Concept');
insert into T2 values(20, 'Concept');
insert into T2 values(110, 'Concept');
insert into T2 values(118, 'Concept');
insert into T2 values(136, 'Concept');
insert into T2 values(128, 'Concept');
insert into T2 values(80, 'Concept');

insert into T3 values(10, 'Grouping');
insert into T3 values(120,'Grouping');
insert into T3 values(130,'Grouping');
insert into T3 values(140,'Grouping');
insert into T3 values(150,'Grouping');
insert into T3 values(160,'Grouping');
insert into T3 values(70,'Grouping');
insert into T3 values(180,'Grouping');
insert into T3 values(260,'Grouping');
insert into T3 values(270,'Grouping');
insert into T3 values(280,'Grouping');
end;
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