In recent years, Nanomaterials are being used in a wide variety of applications due to its varying properties on scaling down from bulk size to nanometers size (10 9m). The surface area to volume ratio plays an important role in Nanoparticles, due to which they become more reactive. Nanotechnology and Nanoparticles based product and application are increased now a days due to various fields. The green synthesis of Selenium nanoparticles using Acalypha indica and Andrographis paniculata exhibits some potential characters and act as a theranostics agents. Comparatively Andrographis paniculata, also known as "King of Bitters," is a plant with various bioactive compounds, including flavonoids, alkaloids, and diterpenoids.