Shell Programming and Scripting

#!/bin/ksh
while read line
do
    cd $line/radmin
    num=0
    # /bin/ls *.txt |          - you are trying list all the TXT files 
    # for file_nm in *.txt
    for file_nm in *.txt
    do 
       check=$(( $RANDOM % 2 ))
       if [ $check -eq 0 ]; then
          continue
       fi
       # (( num = num + 1 ))
       num = $(( $num + 1 ))
       echo /bin/mv $PWD/$file_nm $PWD/t_level${num}.words
       if [ $num -ge 6 ]; then
            break
       fi
    done
done < source.txt