value='"310","00753"'
a=`grep $value  out.txt| cut -f6 -d'"'`
cat=`echo $a | awk '{out=$1;for (k=2;k<=NF;k++){out=sprintf("%s,%s",out,$k);}print out}'`

##</code><code>##

"310","00753","2"

"310","00753","2"

"310","00753","2"

"310","00753","2"

"310","00753","2"

"310","00753","5"

"310","00753","5"

"310","00753","2"

"310","00753","5"

"310","00753","5"

"310","00753","5"

"310","00753","5"

"310","00753","5"

"310","00753","5"