what is the difference between mole fraction in liquid state and mole fraction in vapour phase

There, is no such big difference, they are just obtained in different terms like mole fraction in liquid phase is obtained as no of moles of the substance present in total no. of moles of the mixture, while mole fraction in vapour phase is calculated by vapour pressure of the substance ratio in total pressure of mixture.
Otherwise,  both terms are just samiliar.