It may charge rupees in Home Office cases (5)
I believe the answer is:
rhino
'it may charge' is the definition.
(rhinoceroses charge to attack)
'rupees in home office cases' is the wordplay.
'rupees' becomes 'r' (abbreviation for rupees).
'home office' becomes 'HO' (UK government acronym).
'cases' indicates putting letters inside.
'in' inserted inside 'ho' is 'hino'.
'r'+'hino'='RHINO'
(Other definitions for rhino that I've seen before include "In brief, large thick-skinned animal of Africa" , "big game" , "Powerful herbivorous odd-toed ungulate, informally" , "I may make fearsome charges" , "one might charge in Africa" .)