How to defragment the datafile hwm in EBS R12 database

Question

Hi All,
We are on 1204 E-biziness instance on 11gR2 database.
We have deleted(purged some EGO data and got the huge space in dba_segments. it was around 2.5 gb after purging activity we got
SQL> select sum(bytes/1024/1024/1024) from dba_segments;
SUM(BYTES/1024/1024/1024)
734.867561
SQL>
SQL> select sum(bytes/1024/1024/1024) from dba_data_files;
SUM(BYTES/1024/1024/1024)
2456.70493
SQL>
But in datafile the HWM is not reduced, i checked by moving the big tables, even though i am not getting the space in datafile level, i need to resize my datafile size to 1TB , take backup and clone the target which is having 1TB space.
For example in apps_ts_tx_data we have only 243Gb segments but the datafiles size it is having 1000GB, we have to reduce the datafile size to that 300Gb, how to do it?
=======
SQL> select sum(bytes/1024/1024/1024) from dba_segments where tablespace_name='APPS_TS_TX_DATA';
SUM(BYTES/1024/1024/1024)
243.981201
SQL> select sum(bytes/1024/1024/1024) from dba_data_files where tablespace_name='APPS_TS_TX_DATA';
SUM(BYTES/1024/1024/1024)
1070.2343
SQL>
==========
I thought of creating one tablespace of 300GB and move all objects into new tablespace , drop old tablespace and rename new tablespace to 'APPS_TS_TX_DATA', but we have objects like below, Pl guide me what is the best method of doing this and reduce my database size to 1TB. so that i can accomplish my task
====
SQL> select DISTINCT SEGMENT_TYPE,count(*) FROM DBA_SEGMENTS where tablespace_name='APPS_TS_TX_DATA' group by SEGMENT_TYPE;
SEGMENT_TYPE COUNT(*)
INDEX 275
INDEX PARTITION 509
INDEX SUBPARTITION 96
LOB PARTITION 8
LOB SUBPARTITION 96
LOBINDEX 460
LOBSEGMENT 460
TABLE 14615
TABLE PARTITION 2079
TABLE SUBPARTITION 96
10 rows selected.
====
Thanks in advance..

Answer 1

Please see these docs.
How to Reorganize INV Schema / Reclaim the High Watermark [ID 555058.1]     
Optimizing Database disk space using Alter table shrink space/move compress [ID 1173241.1]
Why is no space released after an ALTER TABLE ... SHRINK? [ID 820043.1]
Various Aspects of Fragmentation [ID 186826.1]
Thanks,
Hussein