I wanted to execute a Test Plan as Below. Example : I wanted every http request should take delay of two minutes
The simplest way is to add a single 'Constant Timer' to your thread group at the same level as your HTTP requests.
Right click Thread Group > Add > Timer > Constant Timer.
Set the timer value to however many milliseconds you need (in your case 120000), and it inserts a delay between all requests in that thread group.