Govt. servant to pay property tax?

My husband is in central govt. job. We r going to purchase a property where major amount is paying by my father and only loan will have to be taken by my husband. Property will be in my name. Will you tell me in this case also my husband has to take prior permission from his department to get involve in this transaction. If yes then at what stage.. At the time of agreement or at the time of registration. To show value what amount he should show?
Registered value or agreement value. Plz guide as per central govt. civil procedure law for employee.