How can you want to cut line separated by dots when your file sample has not cases of such...
As of post#2 What you gave us and explained is far from being clear, especially when you have not given a example of expected output so we can figure out what you ment
I am dubious looking at your code...
Maybe you can set IFS to split the file during reading, then you do not need cut .
For example, read FINAL.txt, echo the new lines, and redirect the whole loop to FINAL2.txt
while IFS="." read f1 f2 f3
do
# compose a new line and print it
echo "$f1.$f2.$f3.$f1"
done < FINAL.txt > FINAL2.txt