Creating Proxies with different frame rates

I am working on Sony Fx6 Footage which was shot on 4k Full Frame with some of them was shot with 25 frames and some clips was shot with 50 frames. When I have created proxy files all of it at once, after that my 50 frames original clip is now 25 frames in proxy. And I can't find any button/option to change frame rates too during the process of creating proxies. And it's my ongoing project.
Thanks in advance.