Hello Sai,
The SAP note 1891560 assumes you have:
=> a primary site - the SAP application (i.e the SAP ERP) running with SAP ASE -
=> and a standby site, where you have installed the SAP ASE, via System Copy, so you have a /sapmnt but no SAP application.
Setting the environment variables dbs_syb_xxx will allow the SAP application to re-direct the client connections to the former standby ASE after the failover.
So under the scenario described above, you don't need to set these environment variables at standby site as you are not supposed to have a SAP application there.
Regards,
Cris