situated
Both are correct, but "situated in the center" is slightly more common.
It is situated in London
The city was situated on the bay.
it is situated at Sarnath
it is situated at Sarnath
i do not know but it was situated in or with napolen on his march
France is not situated on a river.
the RBI is situated in New Delhi
it,s situated in the middle east
It is situated at the abdomen
Vietnam is situated in Southeast Asia.