iOS Question about delegates and story mode

[Nekbeth]

Good day, I want to set a delegate to a controller but they are not connected or segue to another. Imagine a tabBar were you open different controller on each tab. I like to pass an object from tab 4 to tab 1, controller in tab 4 already has a protocol with the it's delegate passing the object. While controller in tab 1 declares this delegate and uses that method to pass the object... The problem is that I can't set it's delegate to self like I did with segues. Is there another way?

I have try (with no success) :

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone" bundle:nil];
    wallController *wallCon = [storyboard instantiateViewControllerWithIdentifier:@"wallID"];
    wallCon.delegateWall = self;

Thank you