How to get the data of selected row in ag grid in angular2?

you can use api.getSelectedRows() that Returns a array of selected rows data.

 public getSelectedRows(){
        let rowsSelection = this.gridOptions.api.getSelectedRows();
        console.info(rowsSelection);
      }

that's work for me.

On template, e.g.:

(rowClicked)='onRowClicked($event)'
(cellClicked)='onCellClicked($event)'
(selectionChanged) = 'onSelectionChanged($event)'

and then on component class:

onRowClicked(event: any) { console.log('row', event); }
onCellClicked(event: any) { console.log('cell', event); }
onSelectionChanged(event: any) { console.log("selection", event); }

Use Chrome console to check the event object contents.