6 ways to say “Good bye” in Russian:

До свида́ния – da svidán’ya – good bye (formal)

Пока́ – paká – bye (informal)

До встре́чи – da fstréchi – see you (neutral)

Уда́чи – udáchi – good luck (neutral)

До свя́зи – da svyázi – till next connection  / will see/hear you (neutral)

Дава́й – daváy – ok, bye (spoken version, informal)