RMAN Backup getting failed with insufficient privilieges error

Hello,

We have upgraded Oracle version from 10.2.0.4 to 11.2.4.3.

After upgrade we have changed oracle home path in configuration file with root privilege  and removed soft link and then created again that link with oracle privilege.

We have networker server with version 8.2.1 installed on AIX OS.
Client has Linux OS installed on it along with 7.6.3 client version and 1.2 NMDA version.

Since upgrade of a database from Oracle version from 10.2.0.4 to 11.2.4.3.  backup is getting failed with insufficient privilege error.

We manually started backup from client it is getting triggered from client side but from NMC it is getting failed.

Please note :- We have created script for backing up oracle database

please help us to resolve this issue.

Thanks and Regards
Dhiraj Dhane