How can I make a script in /etc/init.d start at boot?

Despues de tanto buscar encontre la solucion mas rapida y que funciona, bueno al menos asi me funciono en centos 6.7

$ chkconfig --add myscript 
$ chkconfig --level 2345 myscript on
Para revisar
$ chkconfig --list | grep myscript
ID      Name                Description
0       Halt                Shuts down the system.
1       Single-user Mode    Mode for administrative tasks.
2       Multi-user Mode     Does not configure network interfaces 
and does not export networks services.
3       Multi-user Mode with Networking     Starts the system normally.
4       Not used/User-definable     For special purposes.
5       Start the system normally with appropriate display manager. (with GUI) 
Same as runlevel 3 + display manager.
6       Reboot              Reboots the system.