@aisolutions,
To display a chart inside tooltip, you can create a DOM required for the chart within tooltip using contentFormatter and render the chart on updated event of toolTip. Please take a look at this below code snippet for the same.
toolTip: {
updated: function(e) {
typeof pieChart.destroy === "function" && pieChart.destroy();
pieChart = new CanvasJS.Chart('pie-chart', chartOptions[e.entries[0].dataPoint.label]);
pieChart.render();
},
contentFormatter: function() {
return "<div id='pie-chart' style='width:200px; height:200px;'></div>";
},
}
Also, check out this JSFiddle for complete sample code for rendering the chart within tooltip.

—-
Manoj Mohan
Team CanvasJS