Can I use Red Hat Linux as a file server?

Sure.    And using SAMBA package, it can appear as a windows file server.

Very Well, 

1. For SMB Network you can use samba as fileserver.

2. for unix/linux based NFS share you can export files natively if you have installed nfs-server related packages. 

3. for AFP [ AppleTalk ] you can use netatalk to configure the file and print shares. 

Hope that answers. 

You can use VSFTPD as File server.

https://www.digitalocean.com/community/articles/how-to-set-up-vsftpd-on-centos-6--2

If you want to access it from Windows then use Samba:

http://wiki.centos.org/HowTos/SetUpSamba

go and configure SAMBA on Cent OS .

http://www.howtoforge.com/centos-6.4-samba-standalone-server-with-tdbsam-backend

you can do it using SAMBA

Yes you can use redhat OS as a file server by installing the appropriate package vsftpd-*.rpm and configure iptables to autorize access from external .

yum install vsftpd -y

chkconfig vsftpd on

system-config-firewall

        select ftp service as  trusted service.

the simple answer of your question is simply "YES"