INNIT
Contraction
innit
(informal, low register) Contraction of isn't it.
(British, informal, proscribed) Used as a replacement for any other negative tag question, irrespective of person, number, or verb.
(British, informal, proscribed) Used as a discourse marker.
Usage notes
• When used as a generic tag question in British English, sometimes associated with Multicultural London English, but considered bad or broken English by most educated speakers.
Synonyms
• (isn't it): isn't it, ain't it (slang)
• (tag question): see English tag questions
Source: Wiktionary