Alcohol: There was implied/obvious alcohol consumption and drunken behavior, there was one scene in the dance club where 3 of the main leads, were drinking.
Smoking: there are a couple of scenes where the father of one of the brides-to-be, smokes a cigar (likewise at the same time a "Smoking Kills" msg appears on the screen as well.)
Drugs: No such proper drug use was shown in the film except for one scene, in the jungle where the heroes, get together and are give by the prospective/ future father-in-law, gives them a South asian local intoxicant called "Bhhanngg".