Hi Baldeep,
s2Member’s Login Welcome Page (which should be set up within your s2Member General Settings) can be modified to work like a separate admin area, like we have here at s2Member under My Account. s2Member currently does not support file uploads in its main build, although it could be extended (with a bit of code) to allow file uploads within the Login Welcome Page.
What s2Member cannot do is allow access to the WordPress Dashboard’s file system (or the Dashboard itself), because s2Member both blocks access to /wp-admin/ for users that are within the s2Member Levels, but also does not provide access to any of the features from within the code. So you’ll need to edit s2Member’s Login Welcome Page from within your WordPress Dashboard to fit your needs.
You may want to check out the Unofficial Extensions / Hacks Forum and also keep an eye on the Extensions / Hacks Knowledge Base Category for code to help you along with the file uploads you might need (we have some new posts coming soon, and file uploads are high on the priority).
Let me know if that answers your question.
Cheers!