Hin: अलवर alavar.
‘Salwar Town’ [Salwapur] City, District Rajasthan.
Cunningham’s theory is that Alwar is a corruption of Salwapur [→Salwar→Halawar→Alwar] a.k.a. Saubhanagara/Salwanagar, associated with the tribe of Salwas mentioned numerous times in the Mahabharata epic.
The name may also be connected with the Aravalli Range [Araval(li)pur→Alpur→Alwar], using the common sound shift: Skt/Hin: pur(a)→war, ‘city’.
Alwar is a former princely state with its own City Palace (and now a museum).