When use iron-router, when did onRender is executed?

i using iron-router and user can router between same templates with different data.
(same route! only route params change)
i need make manipulate on the DOM elements each time that data is changed.
when i put it on onRendered function it’s running only at first route!!! or, if i arrive from another route!!!
how can i force route to rerun the onRendered, or where should i write it to run again automatically when data is changed, AFTER the DOM is complete