Hello Ashish,
not sure what exactly do you need but you will find probably most information in development packages SMO*.
For instance, in table SMOHSITEID you will find basic information about sites, SMOF_ERPSH contains additional site information for ERP-type sites (like RFC destination).
Subscriptions and relation to site is stored in tables SMOHSUBSCR and SMOHSUBSIT.
Hope this helps a bit.
Regards,
Dawood.