Hi sachin.b-s!
Thanks for contacting us with your question!
Sadly, there is no possibility to select a row of yAxis in Highcharts Gantt, but you can achieve this in some custom way by adding new events to yAxis labels (using the custom-events plugin) and using Highcharts SVG Renderer.
Demo: https://jsfiddle.net/BlackLabel/n0rjohL2/
API Reference: https://api.highcharts.com/class-refere ... derer#rect
http://blacklabel.github.io/custom_events/
Regards!