Sorry to hear this. I am assuming that this frame member is not detachable. You might first consider having an body shop have a look and make a suggestion. THey straighten car frame tabs and brackets for a living.

For home repair, first take a pic of the opposite side bracket so you know what it should look like - assuming they are mirror images. If you feel competent, pull the fairing, loosen the radiator mount (pull the bolt out completely) then use a slide hammer connected to the fairing mount bolt hole to pull the frame tab more or less back into its former position. You may have to use vise grips, channel locks or an adjustable wrench to tweak the flat portions of the mount back into shape.

Here is a method I used to straighten a bent upper fairing/headlight mount on a Gen1 EX500: after removing the fairing, you can attach an eye bolt facing out with a large washer and nut inside the bent tab. Loop a rope through the eye of the bolt and tie the other end to a tree. Move the bike to a point where the tree is 90º to the bike itself, the rope extending straight out from the frame to the tree. What you are seeking to do it apply the exact opposite force that was used to bend the bracket in order to "unbend" it. Straddling the bike, move it to where the rope is tight. Then by slightly leaning the bike toward the tree, the rope will go slack. Pull the bike quickly back to upright so that the rope will 'tug' on the bent frame piece. Start out very easily and watch the progress as you go. This will take time and patience.

First, I would have a body shop take a look. They might make a deal, hoping that you will bring future business to them.

 

I've fixed radiator mounts similarly bent before on the older model Ninja 500's. Both the old and new 500's all have steel frames so straightening is rather straightforward. What po18guy mentioned is all sound advice, follow it.
The radiator is aluminum and if the mounting tab is bent (it doesn't look to be bent much at all), you'll have to be a little more careful. Aluminum likes to bend once but that's it. Bend it a second time back in the opposite direction too much and it has the tendency to split. I think you'll be fine here since it's not bent much, if at all, but just something to be aware of.

 

I've fixed radiator mounts similarly bent before on the older model Ninja 500's. Both the old and new 500's all have steel frames so straightening is rather straightforward. What po18guy mentioned is all sound advice, follow it.
The radiator is aluminum and if the mounting tab is bent (it doesn't look to be bent much at all), you'll have to be a little more careful. Aluminum likes to bend once but that's it. Bend it a second time back in the opposite direction too much and it has the tendency to split. I think you'll be fine here since it's not bent much, if at all, but just something to be aware of.

When I bought my '87, it had been down at low speed on the left side. I couldn't think of any other way to straighten a bent gen1 fairing stay, so the old maple tree came to mind. Kind of a motorcycle hangman game.