sics / six are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
sics: (verb) urge to attack someone.
six: (noun) the cardinal number that is the sum of five and one. (adjective) denoting a quantity consisting of six items or units.
sics: NA
six: s·IH·k·s
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)