My opinions, If you want to designer Mold , you should learn NX. If you want to design automotive fart should learn Catia. Because Catia will handling surface better than NX, but NX will remove solid and base better than Catia.

Hi shair akber,
This is a good question. I think, If you want to make you professional Mold designer then must use Creo or ProE, NX or Solidworks. But which one you will use it is not important, Important things is Need to Expertism in Mold Design by using any one of attached Software. It is noted that user of Solidworks is more than others.

Thanks,
Md. Rubel Islam