[Solved]-Lasso and D3.js-d3.js

I never used d3.lasso before but looking at this bl.ock using d3 v4, looks like your code is missing a few minor things:

1. Area to be passed to d3 lasso is now done using targetArea

    var lasso = d3.lasso()
     .targetArea(svg)
   

2. Items passed to d3 lasso must be a d3 selection and not a string

   var circles = svg.selectAll("circle")...
   
   var lasso = d3.lasso()
    .items(circles) 
   

And of course, using the actual minified lasso code in a script tag, here's a snippet:

https://bl.ocks.org/shashank2104/f878d660bd9013faa6d48236b5fe9502/67d50a5c7a21c0adfa5ed66ce3dc725f0a45c8c2

Also, I've added some CSS to the selected circles just to differentiate when compared with others:

.selected {
   fill: steelblue;
}

Hope this helps.