Technically yes, but that's not the proper approach. It should run cool if running at rated speeds/not overclocked.
Your temps do seem to be a bit on the higher side, it's probably due to the low quality Thermal grease that comes from the factory wearing off.
Get a syringe of Tuniq TX2 thermal paste (about 150 INR), remove the HS, clean old paste and apply a fresh coat on both the core and the HS contact area.
Temps should drop by 5-10 degrees.

PS: The 9600GT also cuts it's core and mem clock when idle, use a tool like GPU-Z to see it in action