if add row to DataTable
DataRow row = datatable1.NewRow();
row[\"column2\"]=\"column2\";
row[\"column6\"]=\"column6\";
datatable1.Rows.Add(row);
An example of copy row from dataGridView and added a new row in The same dataGridView:
DataTable Dt = new DataTable();
Dt.Columns.Add("Column1");
Dt.Columns.Add("Column2");
DataRow dr = Dt.NewRow();
DataGridViewRow dgvR = (DataGridViewRow)dataGridView1.CurrentRow;
dr[0] = dgvR.Cells[0].Value;
dr[1] = dgvR.Cells[1].Value;
Dt.Rows.Add(dR);
dataGridView1.DataSource = Dt;