Do you think that its possible to transfer corals from our tanks to the ocean and if not do you think that it would be possible to grow a coral that could resist the ocean from just growing it at home
Ok, so, yes and no....
Yes, it is possible, organizations like the Reef Institute, MOTE Marine Labs, Coral Restoration Foundation, etc... all pull the require licenses and permits and do studies to do this exact thing. Alongside universities and scientists they study the spawning, growth, hardiness and viability of the corals they have and work to getting them back on the reef.
Having done a couple dives off in the Keys I've actually spotted a few of their outplanted corals as they are tagged for future studies.
No, I don't the we as hobbyists should be trying to get our corals back on the reefs - at least not directly from tank to reef. Our environments are a lot more regulated than the open ocean/water and a lot of the corals we are keeping may not be native to the area we want to plant them which doesn't make for good ethical distribution.
Would it, in theory, be cool to start a reef in the Keys that is all coral from Fiji? Again, in theory, yes, I'd think that'd be cool but ethically no as if they go invasive we'd have yet another problem on our hands. It may though be something down the line to consider as a means of last resort if we keep losing our native corals here in Florida to where our hurricanes/storms will cause too much damage to the shore if we lose the entire reef.
I've had in the back of my head for a long time the idea of crowd sourcing coral grow out for the native corals for our reef (but fully understand why there are legal hurdles).
Right now, only a handful of people/organizations are allowed to work on propagating Florida Elkhorn & Staghorn corals for planting back on the reef. What if, for say every 10 corals they outplant they were to give one to a hobbyist that's been on a waitlist. Said waitlist would require approval/verification of husbandry skill level, but instead of only being able to use a handful (relatively speaking) of tanks to propagate these corals you could expand this to hundreds or thousands with the requirement that each of the hobbyist must return X size frag to the organization every year or so. Now that organization has a much larger pool to pull from to bring corals back to their location, verify health, acclimate back to ocean conditions, then outplant.