free space in database

Dear Experts,

can some help us in this regard.we have 800G diskgroup allocated but we have only 97G free space left.We want to make some free space.

SQL> Select sum(bytes)/1024/1024/1024 from dba_segments;

SUM(BYTES)/1024/1024/1024

-------------------------

        454.30291

SQL> select

( select sum(bytes)/1024/1024/1024 data_size from dba_data_files ) +

( select nvl(sum(bytes),0)/1024/1024/1024 2  temp_size from dba_temp_files ) +

( select sum(bytes)/1024/1024/1024 redo_size from sys.v_$log ) +

 3  4  5 ( select sum(BLOCK_SIZE*FILE_SIZE_BLKS)/1024/1024/1024 controlfile_size from v$controlfile) "Size in GB"

from

dual

 6  7  8 ;

Size in GB

----------

705.924942

SQL> select NAME,TOTAL_MB/1024,FREE_MB/1024 from v$asm_diskgroup;