urduword.com gives both انتظام intezaam and انتظامیہ intezaamia for "administration," both from arabic via persian. i don't know which is more common. with regards to the urdu equivalent of सरकार, the most commonly used term is definitely حکومت hukoomat, also from arabic via persian. i believe it may have existed previously in hindi as हुक़ूमत, but that word seems to have gone out of use.