Thu, Aug 27, 2015 7:56:29 AM
PoolName,Total GB,Used GB ,Available GB ,Percent Full
Oracle-RAID10,6432.539,6179.295,253.244,96.063
VM_File,45210.379,40726.389,4483.991,90.082
Oracle-RAID5,15025.039,12289.707,2735.332,81.795

Thu, Aug 27, 2015 7:56:29 AM
PoolName       Total GB   Used GB    Available GB   Percent Full
Oracle-RAID10  6432.539   6179.295   253.244        96.063
VM_File        45210.379  40726.389  4483.991       90.082
Oracle-RAID5   15025.039  12289.707  2735.332       81.795

awk -F "," '{print $1"t" $2"t" $3"t" $4"t" $5"t" }' PoolReport.txt

column -s, -t file

Thu             Aug 27     2015 7:56:29 AM
PoolName       Total GB    Used GB          Available GB   Percent Full
Oracle-RAID10  6432.539   6179.295          253.244        96.063
VM_File        45210.379  40726.389         4483.991       90.082
Oracle-RAID5   15025.039  12289.707         2735.332       81.795

{ head -n 1; column -s, -t; } <file

Thu, Aug 27, 2015 7:56:29 AM
PoolName       Total GB    Used GB   Available GB   Percent Full
Oracle-RAID10  6432.539   6179.295   253.244        96.063
VM_File        45210.379  40726.389  4483.991       90.082
Oracle-RAID5   15025.039  12289.707  2735.332       81.795

sed '2,$s/ *, */t/g' PoolReport.txt

awk -F, 'NR==1;NR>1{OFS="t"; print $1,$2,$3,$4,$5}' PoolReport.txt

Thu, Aug 27, 2015 7:56:29 AM
PoolName        Total GB        Used GB Available GB    Percent Full
Oracle-RAID10   6432.539        6179.295        253.244 96.063
VM_File 45210.379       40726.389       4483.991        90.082
 Oracle-RAID5    15025.039       12289.707       2735.332        81.795