Hi @rasika,
You can define the lines as mapbox layers. You need the lon and lat coords for the rectangle vertices. From these coords you define a meshgrid, and then the lines over the meshgrid, as layers of geojson source.
See this example https://community.plotly.com/t/circle-on-scattermapbox-with-coordinates-as-reference/36633/2 on how to draw a circle as a layer.