Dear Zanaib ali,
Duties of Administration are vast. If the position is Director - Administration then HR, finance, Purchase, Logistic all report to him.
At lower level, Admin is responsible for:
Maintenance of Parking facilities for the employees
Maintenance of the Staff Cafe or Canteen
Maintenance of Gym
Maintenance of fire systems
Maintenance of Security systems - physical and through systems
Maintenance of employee accommodation
and many others
for your convenience, I have JD of CGM - Admin. this will give you the idea of what admin is supposed to do.
Thanks,
Dinesh V Divekar