Hello Ramakrishna,
I already checked database by executing command "select status from v$instance;"
the result is OPEN.
I have checked many times keeping DB Open and mount phase also but same issue repeated.
tnsping W89/willsys89/IP i have checked already pinging properly.
I have checked /sapmnt/W89/profile/oracle. tnsnames.ora is existing and same in both locations.
Thanks,
Karthik