#!/bin/bash
FILE2=/usr/local/app/command_file.log
while read line; do
command=$(echo $line)
# The variable "command" is never used.  Why define it?
log=$(echo $line | awk -F'"' '{$0=$2}1')
count=$(ps aux | grep -i "tscV6Connector" | grep -v "grep" | wc -l)
# Change: grep -i "tscV6Connector" | grep -v "grep"
# in the pipeline above to: grep -i "[t]scV6Connector"
# and your script will run faster.
instance=$(echo $line | awk -F'"' '{$0=$4}1')
if [ $count -le 6 ];
then 
    echo "Running command for "$log" with name starting with "$instance"...."
    nohup "additional_command_parameters" > /usr/local/app/log/"$log"/"$log_$instance".log &
    sleep 10    #Sleep time for the extraction process.
# The variable "log_" has not been defined.  Should the output above be
# redirected to:  /usr/local/app/log/"$log/${log}_$instance.log"
    now1=$(date +'%d/%m/%Y %X');
    echo -e "*** TSO *** "$now1": Started extraction for MAGIC object type "$log" with name starting "$instance" process PID = "$!""
else 
    now2=$(date +'%d/%m/%Y %X');
    echo -e "*** TSO *** "$now2": Total MQL extraction process reached "$count"....\n*** TSO *** "$now2": waiting for previous process PID "$!" to complete"
    wait $!;    #Main wait statement when count >=7. Once wait is over, run the next command after wait.
    nohup "additional_command_parameters" > /usr/local/app/log/"$log"/"$log_$instance".log &
# See note above about ${log}_ versus $log_.
    sleep 10;    #Sleep time for the last MQL which was waiting before log files.
    now=$(date +'%d/%m/%Y %X');
# In the line above you define the variable "now".
# In the line below you use the undefined variable "now3".
    echo -e "*** TSO *** "$now3": Started extraction for MAGIC object type "$log" with name starting "$instance" process PID = "$!"\n*** TSO *** "$now3": Total number of extraction MQLs on DB are = "$count"\n"
fi
done < $FILE2