EDIT: When I go to https://workbench.developerforce.com and I do not see the field which I have added, is that due to Managed release installed?
I have installed the Managed package in my org and then I have added few new fields to that custom object and I can see that fields are there but when I try to do SOQL query I get this error:
SELECT id,name,Address__c FROM Employee__c
ERROR at Row:1:Column:30 No such column 'Address__c' on entity 'Employee__c'. If you are attempting to use a custom field, be sure to append the '__c' after the custom field name. Please reference your WSDL or the describe call for the appropriate names.