This is the 11487th most frequent Swedish word.
nåt
"Something."
Here, 'nåt' is used as an informal shorthand for 'något', used to signify 'something'.
Nåt intressant händer alltid på helgerna.
Something interesting always happens on weekends.
In this sentence, 'nåt' again replaces 'något', meaning 'anything', showing informality.
Säg till om du behöver nåt.
Let me know if you need anything.
The word 'nåt' is acting as 'some', replacing 'något', indicating a specific but unspecific issue.