Hello Kunal,
There is an Agentry Client version 6.1.7.2 available on the App Store from 20th of October 2015. According to the "What's New" section this client has support for iOS9. You might need to configure your Agentry Server (I guess version 6.0.*) to work with this client.
Note: Please have in mind that Agentry Client 6.1.* is supposed to run against Agentry Server 6.1.* which is running on SMP2.3. For this reason "side effects" might occur. But it is always worth trying if you have no option to downgrade to iOS8 or to quickly migrate to SMP2.3 or better SMP3.0
Good luck,
V.