Dear @Mohabat,
Welcome to the Wefugees Community and thank you for reaching out to us.
In general, it is possible to apply for asylum as student in Germany. My colleague Éanna gave some more information on this topic here before. Your reasons to apply for asylum will be checked individually and carefully by the German authorities (the so-called BAMF). Only if you are granted protection (positive outcome of your asylum procedure), there will be an option to apply for family reunification (not if your asylum will be rejected). Under certain conditions it is also possible to come as a student together with your family to Germany - or to reunite once you are here. In this case, you have to prove that you can secure your and your family's livelihood and that you are financing your life expences without the assistance of public funds (as written also here at a German government website).
I hope this helps and please don't hesitate to get back to us with any further questions.
All the best,
Meike