In one of requirment, I had to set ulimit on one of my machine to unlimited.

For this I changed following in /etc/security/limits.conf as below

# End of file
oracle   soft   nofile    unlimited
oracle   hard   nofile    unlimited
oracle   soft   nproc    131072
oracle   hard   nproc    131072
oracle   soft   core    unlimited
oracle   hard   core    unlimited
oracle   soft   memlock    50000000
oracle   hard   memlock    50000000

*           soft    nofile          unlimited
*           hard    nofile          unlimited

and changed /etc/profile

if [ $USER = "oracle" ]; then
        if [ $SHELL = "/bin/ksh" ]; then
              ulimit -p unlimited
              ulimit -n unlimited
        else
              ulimit -u unlimited -n unlimited
        fi
fi

I logged out. I am not able to connect ot machine at all. could you please someone help on this.