The Sony FX3 is a compact full-frame cinema camera used in Nepal for documentaries, gimbals, and small crews. The FX6 is larger, with built-in ND and a more traditional video layout. Both take Sony E-mount lenses, so glass and many accessories move between them.
Choose FX3 for size and IBIS. Choose FX6 for onboard ND and shoulder or tripod days. Availability in Kathmandu changes — open live rental and buy listings. Ask your cinematographer which body they already have media and cages for.