in what case people sey " take it easy" ?

When we want to calm someone down, we use 'take it easy'.
example:
Take it easy. We'll take care of everything.

In general, the term "take it easy" means the person saying it thinks you should calm down. It may indicate that person thinks you are too angry or you are too scared you are too excited for the situation.

when someone gets very excited, be it mad excited or happy excited. you say, "take it easy." it means calm down.