Where is a conjunction that is used to connect with a noun that denotes a place.
Delhi where policy is made is the capital of India.
Trackers camped on the height of the mountain where there was snow everywhere.
In which is also a conjunction that is used to connect with a noun that is not literally a place but gives the sense of place.
The company is in a situation where it does not have any growth. Incorrect
The company is in a situation in which it does not have any growth. Correct