The designing softwares vary depending on the part to be designed. Some of the good designing softwares I am  listing below:

Autocadd

Rhinoceros

Catia

Solidworks

Ansys

3Ds max

Sketchbook designer

Lightwave

Blender

Adobe photoshop

Hope you find it helpful

let me know in the comment box if you are having any further doubts

thanks

Good Luck!