The GeForce GT 630 is just a rebadged GeForce GT 440. They both use the same Fermi GF108 GPU.
That graphics card should draw less than 5 Amps from the +12V rail even while running GPU stress testing.
If your Intex Power Supply Expert IT-20F1BC is actually able to output a continuous 20 Amps on its +12V rail then it meets the minimum power supply requirements. If the 20 Amps is a peak specification and not a continuous specification then it becomes doubtful.