Fixed matches is a contract deal usually involving some set of anonymous group ( usually top influential wealthy men) who have come together to attain some certain goals ( making huge money) from football by paying huge amount of money to the clubs, Referee's, Teammates, And Involvement of some online bookmarks to make their intentions right about the match to play. We can't say fixed matches is illegal neither can we say is legal but note that every operation involved in it is meant to be private