Located = refers to hypothetical location at large. example: Howrah is located somewhere in West Bengal. Situated = refers to rather a precise or complete location. example: My office is situated next to IDBI bank in Lower Parel, Mumbai Hope it helps !

For me, there is not much difference, except that situated emphasises the physicality of location more. (I know I'm getting deep, I don't even know how I did that haha). In any case, I say "located" a lot and "situated" rarely to describe where something is.