I did try removing Sony DSLR Alpha-A77 M2 (Control)_config.xml in ~/.indi, this did not seem to have any effect - when indi connects to the camera, image size reverts back to 6058x4012. I also tried manually editing the config, and found
<newNumberVector device="Sony DSLR Alpha-A77 M2 (Control)" name="CCD_INFO"> <oneNumber name="CCD_MAX_X"> 6000 </oneNumber> <oneNumber name="CCD_MAX_Y"> 4000 </oneNumber>
<newNumberVector device="Sony DSLR Alpha-A77 M2 (Control)" name="CCD_FRAME"> <oneNumber name="X"> 0 </oneNumber> <oneNumber name="Y"> 0 </oneNumber> <oneNumber name="WIDTH"> 6000 </oneNumber> <oneNumber name="HEIGHT"> 4000 </oneNumber> </newNumberVector>