Hi Saloni,
as it seems, the schema is already present in your database.
If it's empty, you can use it, if not, you'll have to drop and recreate it.
If we've made a mistake in our installation scripts that causes the CREATE AUDIT_TRAIL statement to be executed twice, well, that's fine as well.
We need that table, but we don't need two of them ;-) In that case, just ignore the error.
HTH
Best regards,
Ronald