Good evening @Dinesh911,
You cannot disable internet, but you can block one or more devices to use the internet from a time x to a time y (e.g: 22p.m to 7a.m).
To do this, you need to connect to the Horizon box as an administrator :
Open an internet browser > Write http://gwlogin.net/ or http://192.168.192.1 > Enter admin as user and password.
There is a tab “Parental Control” where you can manage the internet’s use of some devices.
If you need more help, do not hesitate to say it to me