I will make this clear now
When we activate mybb default gd captcha plugin, it will appear on all places where authentication is required like registration page, guest posting, contact pages and all. Now, i installed recaptcha III, which only works on registration page.
So if i disable the default gd captcha it will remove that from registration page and only recaptcha appears, which is fine. But, i'm loosing the gd captcha in contact page, so spammers are annoying my inbox with spam contacts.
Now, what i want is, i would like to activate the default gd captcha too and remove its functionality completely from registration page only which will make it appear on other places like contact pages, guest posting and all. The recaptcha serves the authentication at registration page.
I'm much delighted if any one recommends a solution atleast on how to use the recaptcha functionality in other places.