Not able to alter table in Hive

In Big data labs:i have created a db.Now when i create a table under it i am able to see it through the command hadoop fs -ls //apps/hive/warehouse/.db/table.
But when in Hive prompt i use the db and type show tables i dont see any tables.
When i try to add a partition in the same table i get a permissions errors.

Request you help in this regards as i am stuck and not able to go ahead with partitioning topics because of this error

@apurba28 - First switch to db database
use db;
show tables;

try with alter once you switch to your database, if you still face the problem keep posted with command what you are trying.