The invention relates to a composite, comprising a phosphate salt of an element selected from lanthanide series and an organic phosphonic acid, wherein the phosphate salt is a phosphate salt of Lanthanum or Cerium or mixture thereof and the organic phosphonic acid is selected from the group consisting of alkyl, allyl, and aryl phosphonic acids, wherein alkyl groups comprises of C2-25 alkyl chains with general formula CnH2n+1, branched or unsaturated alkyl, aryl groups comprises of Ph, benzyl, or heteroaryl including pyridyl or terpyridynyl, aryl groups is optionally substituted with halogen, OH, -CN, OR1-30, NH1-2R0-30, N(R1-30)2, COOH, COOR1-30, wherein R is a C1-30 alkyl group; wherein the phosphate salt of an element and the organic phosphonic acid is in a ratio of 20:1 - 4:1. The invention also relates to a process for preparing the composite, comprising: (a) activating a phosphate salt of an element selected from lanthanide series by acid treatment to obtain an activated phosphate salt; (b) mixing the activated phosphate salt obtained in step (a) with an organic phosphonic acid in a ratio of 20:1 - 4:1 in an organic solvent to obtain a mixture; (c) stirring the mixture obtained in step (b) at 25 - 28° for 72 h followed by centrifugation at 5000 rpm for 10 min twice and drying for 12 h at 70° in hot air oven to obtain the composite. A water repellent surface, comprising a substrate coated with the composition of the invention, wherein the substrate is selected from the group consisting of glass, wood, plastic, metal, cloth, and paper, is also claimed.