sqlplus -s rcrp/rcrp<<EOF
update PRICE_CLASS_DET set PCD_VALUE=1 where PCD_ID=11313;
commit;
exit;
EOF

if [ $? != 0 ]
then
echo "The Tariff Group Revert Back to Residential Type Customer for Antillia is not completed." | mailx -s "A
NTILLIA BOC ERROR $0" $MAILTO
exit;
fi

The above if condition is not able to catch the error from sqlplus command.