Red line around city

https://preview.redd.it/gy0jmnlud7jh1.png?width=1057&format=png&auto=webp&s=79c1f19d5bb57d5e88e32f13ab1eb7c0b875c585

Recently i have been searching about this red boundary shown on google earth when clicked on a city, does this represent the Municipal Boundary or would that be different for a city, since for classifying a land as rural agricultural it needs to be 2km away from such Municipals, if not where can i get the official Municipal boundary map to measure the aerial distance for income tax exemption law on sale. Thankyou for your help :).