Q. I want to drive 600 km in a day at 46 degree atmospheric temperature with Celerio X ZXi AMT. Suggest me is there any problem to drive long?

All the technical stuff aside modern day combustion engines reliability is not effected by outside temperature yes ofcourse engines efficiency might alter due to heat or cold temperatures but nothing major if your not racing it for lap times, honestly from personal experience i drove Suzuki estilo for 450km last may yes ofcourse it wasn't 46° but it was summer in a car which is basically the same car with same engine as celerio so i had no concerns yes obviously if cars service was done a few months back so it would be better to just check coolant level and oil level just to be sure.

You see you drive in early morning start around 5am to 8 am again halt for half an hour and start drive up to 11..if it's very hot then do not drive again you start after 4pm to 9 PM or 10 u can go comfortably

Celerio comes with k series engine that mean aluminum alloy engine that make engine heat efficient so its will not get affected by 46℃...since ur drive is so high just check coolent and oil before going.