#! /bin/bash

#retrieve current date and month
da_date="`date +%d`"
#da_date="2"
da_month=`date "+%m"`
#da_month="02"

 prev_date=0
 prev_mon=0
da_year=`date "+%Y"`
# Check  whether date is above 3
if [ "$da_date" -ge "3" ];then
  da_dat=`expr $da_date - 3`
  da_dat="""$da_dat"
else
 # If date is 2, it display the record of 2,1 and last day of previous month
 if  [ "$da_date" -eq "2" ];then
  da_dat=2
  prev_mon=`expr $da_month - 1`
  prev_date=`cal $prev_mon $da_year | xargs -n1 | tail -1`
  prev_date="""$prev_date"
 else
 # If date is 1, it display the record of 1 and last two days of previous month
   da_dat=1
  prev_mon=`expr $da_month - 1`
  prev_date=`cal $prev_mon $da_year | xargs -n1 | tail -2| head -1`
  prev_date="""$prev_date"

  fi
fi

while read line1
do
line=`echo $line1 |grep -v Employee  |  awk '{if($2=="M") print $4}'`
if [ ! -z "$line" ];then
op_da=`echo $line | awk -F/ '{print $2}'`
op_mo=`echo $line | awk -F/ '{print $1}'`
op_year=`echo $line | awk -F/ '{print $3}'`

#if date is 3 and above following block will be executed
if [ \( \( "$da_dat" -eq "`expr $op_da - 3`" \) -o  \( "$da_dat" -eq "`expr $op_da - 2`" \) -o  \( "$da_dat" -eq "`expr $op_da - 1`" \) \) \
 -a \( "$op_mo" -eq "$da_month" \) -a \( "$op_year" -eq "$da_year" \) -a \( "$prev_date" -eq "0" \)  ];then
 echo $line1 | awk '{print $1}'
 #echo $line1
fi

#if date is 2 or 1 following block will be executed
if [ \( "$da_dat" -lt "3" \) -a \( \
 \( \( "$op_da" -ge "$prev_date" \) -a \( "$op_mo" -eq "$prev_mon" \) -a "$op_year" -eq "$da_year" \) -o \
\( \( "$op_da" -le "$da_dat" \) -a  \( "$op_mo" -eq "$da_month" \) -a \( "$op_year" -eq "$da_year" \) \) \) ];then

 echo $line1 | awk '{print $1}'
 #echo $line1
fi

fi
done < inp6

Employee  Gender    NAME      Last Login
    ID                                       Time
-------------------------------------------------
210125       M         ABC         02/03/2012 08:07
451235       F         EFG         02/02/2012 16:53
241567       M         GHI         02/01/2012 14:03
314584       M         JKL         02/02/2012 12:43
123456       M         MNO         02/12/2012 00:00
654321       F         PQR         02/12/2012 00:00
210120       M         ZVF         02/03/2012 08:07
451230       F         UNM         02/02/2012 16:53
241560       M         IOP         02/05/2012 14:03
314580       M         UOP         02/04/2012 12:43
123450       M         MNN         02/12/2012 00:00
654320       F         PQP         02/11/2012 00:00
65430       M         PQP         01/30/2012 00:00
65432       M         PQP         01/31/2012 00:00
245432       M         PQP         01/29/2012 00:00