The below mentioned script can be used to check the table Fragmentation

Column owner   Format A6
Column table_name Format A25
Column "Fragmented-Actual"    Format A15
Column "Fragmented Size"   Format A17
Column "Actual Data Size"   Format A17

SELECT 
owner,table_name,
round((blocks*8),2)||' kb' "Fragmented Size",
round((num_rows*avg_row_len/1024),2)||' kb' "Actual Data Size",
(round((blocks*8),2) - round((num_rows*avg_row_len/1024),2) )||' kb' "Fragmented-Actual"
FROM dba_tables
WHERE table_name = '&table_name' ;