Thineswar :
there's no such thing as a compatible case. the only thing you need to pay attention to is the positioning of the fans and the side window.
before you get the gpu, make sure it has a pci express slot for it.
for the psu, make sure the 12v rail is sufficient
edit: why would you even want to change the case? you could spend that money on a better gpu
Enthusiast GPUs rarely fit OEM PC cases, hence the case change.
To the OP:
What you need to check is if your PC motherboard conforms to the ATX/ mATX/ ITX standard, since many OEM motherboards have proprietary standards, or are build to rare standards (Eg: BTX.). You can normally find this info on the manufacturer's product page.
Next, a GTX 960 needs a decent power supply to ensure it isn't damaged. It needs a PSU that is 400W minimum. However, even if your PSU is above 400W, it would probably be a good idea to change it to something like a Corsair, EVGA, Seasonic, Cooler Master, Super Flower or Antec PSU, since OEM PSUs rarely output the Wattage they claim to, and that could damage the 960. Also before buying any power supply, check that your mother board has the 24 pin ATX power connector, and the 8/4 pin CPU power connector, since many OEM power supplies are proprietary, and cannot be easily swapped out.
24 pin ATX power connector.
8 pin CPU power connector (, 4 pin has two less columns of pins.).
Finally, check that the case you are getting can accommodate the length of the GTX 960.
Edit: Looks like you are lucky!! The PC you have does have an mATX motherboard, so any ATX or mATX case will do (the bitfenix is fine.). Your power supply also is a standard one, so you can swap it out with a better one with no problems:
The bitfenix should accommodate the 960 without a problem, but only if it is this version of it:
http://www.bitfenix.com/global/en/products/chassis/colossus/
or the Colossus M:
http://www.bitfenix.com/global/en/products/chassis/colossus-micro-atx/
As for the new PSU, I recommend this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151124