Steps to be followed:
1) Create connection string at catalog database.
2) At catalog database, create one new user or use existing user and give that user a recovery_catalog_owner privilege.
3)
Login into RMAN with connection string
a) export ORACLE_SID=
b) rman target catalog @connection string
4) rman> create catalog;
5) register database;

1 User has rated as useful.
Login to rate this answer.
Steps to be followed:
1) Create connection string at catalog database.
2) At catalog database create one new user or use existing user and give that user
a recovery_catalog_owner privilege.
3)Login into RMAN with connection string
a) export ORACLE_SID
b) rman target catalog @connection string
4) rman> create catalog;
5) register database;

1 User has rated as useful.
Login to rate this answer.