Thank you for reaching out to us again today.
If by registering your marriage, you intend to apply for family reunion so you can join your wife in Germany, here is all the necessary information you need from the German Missions in Pakistan: https://pakistan.diplo.de/pk-en/service/05-VisaEinreise/1-visa-fz-seite/1676108
The website lists all the documents you need to hand in and what steps you need to take.
Here is the list as a PDF: https://pakistan.diplo.de/blob/1673178/eee25263c79ed8646c7d67daf4edf4bc/7-merkblatt-fz-data.pdf
Regarding the processing time, the website only states "several months". Unfortunately, German bureaucracy is not the fastest.
I hope this helps. Let us know if you have any more questions and feel free to use the comment function below to keep the conversation on this thread! :-)