These were the locations of their settlements allotted as their territory

1 Chronicles 6:49-81

Their fellow Levites were assigned to all the other duties of the tabernacle, the house of God. But Aaron and his descendants were the ones who presented offerings on the altar of burnt offering and on the altar of incense in connection with all that was done in the Most Holy Place, making atonement for Israel, in accordance with all that Moses the servant of God had commanded.

These were the locations of their settlements allotted as their territory (they were assigned to the descendants of Aaron who were from the Kohathite clan, because the first lot was for them)

The total number of towns distributed among the Kohathite clans came to thirteen.

The rest of Kohath’s descendants were allotted ten towns from the clans of half the tribe of Manasseh.

The descendants of Gershon, clan by clan, were allotted thirteen towns from the tribes of Issachar, Asher and Naphtali, and from the part of the tribe of Manasseh that is in Bashan.

The descendants of Merari, clan by clan, were allotted twelve towns from the tribes of Reuben, Gad and Zebulun.

Why?

Elvites got the land from other tribes by taking lots. It is fair to every tribe.

How?

The Lord takes care of his servants' service in the Temple and has their land and home to live in.