Dear @Mohammadzai,
Welcome to the Wefugees Community and thank you for your question.
I am not a Dublin-procedure expert - therefore, I will also link my dear colleague @mbeon-Éanna here. As fas as I know, the time limit of 6 months in which Germany has time to deport you to the country responsible for your asylum procedure (according to the Dublin regulation) will start from the beginning after the court rejection (the so-called "Überstellungsfrist"). After these 6 months, your asylum application may be assessed in Germany.
However, I hope that my colleague can provide more details.
In any case, please also don't hesitate to get back to us with any further questions.
All the best,
Meike