Yes all 4 DBs are in the same ora home.

Yes i am able to shut and start all 4 DBs manually.

Attached below is my oratab file :-

#

# This file is used by ORACLE utilities. It is created by root.sh
# and updated by the Database Configuration Assistant when creating
# a database.

# A colon, ':', is used as the field terminator. A new line terminates
# the entry. Lines beginning with a pound sign, '#', are comments.
#
# Entries are of the form:
# $ORACLE_SID:$ORACLE_HOME::
#
# The first and second fields are the system identifier and home
# directory of the database respectively. The third filed indicates
# to the dbstart utility that the database should , "Y", or should not,
# "N", be brought up at system boot time.
#
# Multiple entries with the same $ORACLE_SID are not allowed.
#
#
*:/oracle/app/oracle/product/8.1.7:N
whl2:/oracle/app/oracle/product/8.1.7:Y
whlr:/oracle/app/oracle/product/8.1.7:Y
ialdb2:/oracle/app/oracle/product/8.1.7:Y
whlp:/oracle/app/oracle/product/8.1.7:Y

TQ.