Abhatt:
What t4 templates do is generating classes for you and you need to keep them, unless you decide to use another t4 template. For instance, you may want to design you database but after that decide to use code first to take advantage of code first approach, in that case after designing the database you will add another t4 template named "EF 5.x DbContext Fluent Generator for C#" and that template creates the poco class and all mappings for you.
Whenever you are adding a controller mvc uses scaffolding to create controller's methods and views. However, if you want to have more control on how to generate them, you may install MVCScaffolding from package manager console. Having MVCScaffolding installed, you will be able to customize t4 templates. For more info check out MVC Scaffolding project on CodePlex: http://mvcscaffolding.codeplex.com/ also there is another good one: http://www.codeproject.com/Articles/468777/Code-First-with-Entity-Framework-5-using-MVC4-and