Avinash,
I knew few basic things in security aspect around SRM 7.0
SRM7.0 ehp1 can work with Portal /NWBC . If it is integrated with NWBC , Navigation and UI can be controlled with PFCG roles whereas the same should be controlled via portal roles in portal integration.
If it is portal , then you may work with portal team to design the custom portal roles.
Thanks,Krishna