It seems we need to create adhoc profiles separately for iPhone applications. A user with administration privilege cannot create adhoc distribution profile. Only chairperson can create that.
Secondly only 100 devices can be added. Is there a way out ?
Can I convert a developer build to adhoc build ?
Yes, you have to create seperate provisioning profiles for
AdHoc Distribution profiles are limited to 100 devices per year, it is designed to be used for testing only.
You should have separate builds in Xcode corresponding to these profiles.
Who can create those has been decided by your chairperson when setting up the account. You'll need to sort that out internally.