Hey @Mayank_Budhiraja , welcome to the Babylon community.
Babylon has mesh outline built in. You have set the mesh.renderOutline = true
in the mesh object (see the following playground: renderOutline - order | Babylon.js Playground)
If you are interested in a more custom solution there a plenty of posts here in the forum from people that already implemented their own solution.
See for example this thread: Custom outline shader - Questions - Babylon.js
And this demo: Outline Post-Process - Demos and projects - Babylon.js