Hi Neethu,
Thank you for your interest in Syncfusion products.
If you want to drag the reference line to a different location by dragging to that place, you can use the Interactive cursor feature.
Please take a look into the browser sample from the below location:
\\users\My Documents\Syncfusion\EssentialStudio\X.X.X.X\Windows\Chart.Windows\Samples\2.0\User Interaction\ChartInteractiveCursor\cs
Online documentation link for interactive cursor:
http://www2.syncfusion.com/ug_62/chart/InteractiveCursorChartHighlight.htmlTake a look into the sample, if this is not meet your requirement. Please provide some more information, so that we can provide you the exact solution.
Best Regards,
Bhuvana