The only real physical differences between Rava and Veena are that Rava have bigger eyebrows while Veena have smaller eyebrows, Rava's eyes are also brighter like they have a natural glow to them while Veena's are darker but I'd also say more natural looking. That last big difference is skin tones, Rava's have medium to dark skin tones with lots of browns and some grays tones, Veena skin tones are more pale with their darkest tones being close to Rava's lightest tones and being most made up of tan tones with some pale blue and olive tones. Their ears are actually a customization option with 4 choices none of which are limited to a specific clan

For a full look at their customization options I suggest watching these videos.

Rava: https://youtu.be/ycqHnQQm2ys
Veena: https://youtu.be/VVLzzUZVYz8