El Capitan version 10.11.6 compatibility

I'm on OS El Capitan version 10.11.6 and have a Vestax VCI-100 midi controller. Are they compatible if I use an M-Audio Fast Track Pro external sound card and buy Traktor Pro 2 please? Since Traktor Pro 1 is not supported by El Capitan.

Moreover, if I move to Sierra, will everything still work fine?

Thanks