If your video was shot in 60i your Project frame rate will have to be 29.97
If FCPCX does not recognize the format of your video when you drop it onto your Project timeline (as you have mentioned on the other forum) there may be something wrong with your ProRes file. The external app you are using is not really a highly recommended video converter for MTS files.
Why don't you just import your footage in FCPX instead of converting it with an external application? Just connect your camera to your computer, launch FCPX and open the Import window. Your camera should appear in the Device list, select it and import the footage. If you want you always can optimize your imported media to ProRes while importing, or you can import the footage first and the convert the imported files to ProRes from within the Event browser. Couldn't be easier.