Authorization setting for combined applications

Hi,
I am working on a scenario where I need to combine three applications into one (Project Requirement). I link the three applications on a web page and which ever link is clicked, I redirect it to that page.
My application sturcture looks as below
MainPage
- Folder1 with App1 (uses Active Directory group for authentication)
  - SubPages
- Folder2 with App2 (Uses Membership roles and users)
  - SubPages
- Folder3 with App3 (Uses Other logins for oracle database)
  - SubPages
Is it possible to provide authorization only for my App2 based on the role created in membership.
For eg: There is user1 with role1 and user2 with role2 but i need to allow only user1 with role1.
When I was checking this scenario in the ASP.NET configuration settings to modify, it has the allow all permisions which is disabled to modify and it is given that Rules that appear ...