In Grand 2, You don’t have to install any third party applications in order to block the incoming calls. This feature is by default available on the device. Not only blocking the incoming call you can but also disable the notifications like messages.
From Settings go to Device and tap on Blocking mode. From the Blocking mode screen enable this feature. On this screen there are features like Block incoming calls, Disable notifications, Disable alarm and timer. When Blocking incoming calls feature is enabled you will not receive any calls. You could allow calls from the contacts that you have on your phone or you could allow contacts that are marked as favourites.
When you set the option to allow contacts from your contact list you will not receive any other calls other than the one from your contacts and when set to favourites no calls will be received other the one from your favourite list.
Other features are disabling the notifications like message or any alerts. You could also set the time from and to so that between these times the block mode will function. When set to Always it will work always.