It means party in Tamil.
That has no meaning in English, try eastern languages.
Katchi has a number of meaning the two I know of is (1) in Punjabi means "Knickers" or the feminine version of "Katcha" which is like the Indian version of boxer shorts and (2) a derogatory term used by a Punjabi to refer to someone who is Gujarati.
Tamil Desiyak Katchi was created in 1995.
Perunthalaivar Makkal Katchi was created in 2011.
Makkal Manadu Katchi was created in 2006.
Viduthalai Chiruthaigal Katchi was created in 1972.
Pattali Makkal Katchi was created in 1999.
Hindu Makkal Katchi was created in 1993.
All India Samathuva Makkal Katchi was created in 2007.
Ahila India Naadalum Makkal Katchi was created in 2009.
katchi
Perween Rahman has written: 'Katchi abadis of Karachi'