You must edit two files:

/etc/security/limits.conf

The case of nprocs is particular in RHEL:

/etc/security/limits.d/90-nproc.conf

You can add more limits configuration files in the directory:

/etc/security/limits.d

Examples:

root         soft    nofile      8192
root         hard   nofile      8192
netcool      soft    nofile      8192
netcool      hard   nofile      8192