Nowadays women wear only green or full-color dresses in mehndi ceremonies. You can design a light weighted lehenga like Mouni Roy.
As a wedding function, the trend of organizing a cocktail party is very popular nowadays. You can give yourself a stylish look by wearing a ruffle saree like Mouni Roy.
If your engagement is in summer, you can also choose colors like Light Blue, Gray, Pistachio Green, Light Purple, such colors give you a somber look, in this look Mouni is wearing a net color scarf of a gray color.