Sorry, my question was terribly wrong.
Under project>Budget and forecasting, I have enabled the use budget control. This project belongs to LE B and when I used it in the expense report in LE B it was throwing the error but when I used the same pricect in IC expense it was not throwing the error. So does that mean, the project set up I made(enabling Budget control) is respective to only Legal entity B and does not affect Legal entity A?