hi i am able to set the deny permissions as default permissions.
This is not very clear. Are you going to the IT policy and then are you changing the policy?
If so, the behaviour is a bit different for different policies. Some policies that deny something also lock that control on the phone and users can't change it. Some others don't. So it depends on what you want to change.
Please describe exactly what you want to deny and what you want to allow.