hi ashok,
ur queries about spectrum in diffrent area.yes it is totally restricted by the govt. for diffrent places.only applicable commercial spectrum for diffrent areas u can use with permission of WPC after clearance of SACFA.
regarding ur second query. defence purpose used spectrum can be vacated but it can be given after permitted by WPC only.
WPC is a wireless protection committee of india having diffrent authorities as member like all forces,prasar bharti,BCI.and others containing more than 12 members by the govt.