Hi there...i wanna get a best software to control the fan speed ....

Video card fan or CPU fan?
for video card, you can use Rivatuner.
for CPU im not sure

chassis fan and cpu fan...

I guess...... Laval soft Everest professional edition can detect those GPU FAN, CPU Fan & chassis fan too.....

What fan is it, is it gpu, cpu or chasis fan?
Do u already try speedfan? (depend on ur chip or hardware) correct me if im wrong , sorry

lavasoft everest detect temperature is it reliable? coz i use core temp and everest both gave me a total diff value for cpu temp ...wondering which wan more correct

how bout nvidia ntune..there's an option for controlling fan but i dun remember which fan..

it depends on ur hardware also....
wat is the spec of your rig?