Afterwards
Larger bolt
or
helicoil
or
threaded insert
Or make an little L bracket that attached to the other nut there and then attach to the bracket.
I would run a thread chaser to clean up the treads & try to use the same size bolt before i would go through the trouble of a heil-coil
![My Two Cents :twocents:](https://board.marlincrawler.com/Smileys/marlin/twocents.gif)