Joomla access process

Need to create a app to add to my website. After user registry in the site, we need to gather more information in the registered area... one data should be the group that is in our organization... after that we should create a table in the front-end where we can give some users the administrative rights to change and verified the data as well as the level of access... The level to give to the admins should come from the top, seven levels down (there are 7 level of access)... every level should see only an area the Joomla website.