How can I re-order the same order? I want to have a button on order information page when clicked the same order should be repeated. How can I put the same products again in the cart or simply re-order again?
This would probably require a plugin with a controller which you could post the order id to when clicking the button. Within the controller you could then query the database to get each line item and add it to the cart within a service if it is in stock and still enabled. The final step would then be to redirect to the basket or posted url.

The docs here should help you get started: https://craftcms.com/docs/plugins/controllers