There are liquids of different densities together in a container. what will happen to the liquid with the lowest density?

The process by which two liquids are mixed in all proportion, dissolving completely and forming a homogenous solution is known as miscibility. For example,  alcohols and ethanol are miscible with water.

But two liquids of different densities never mix with each other and in that case, it is considered as the immiscibility. For example, Oil and water are both of different densities and they never mix, whereas the oil being less denser floats above the layer of water.

Thus, when there are liquids of variable densities that are present together within a container, then the lowest density liquid will float on the top of the entire solution.