I thought always that there are 4 rakats sunnah before and 4 rakats sunnah after the Jumuah prayer.Now recently a brother said to me that we must pray 6 rakat sunnah prayer after Jumuah
Answer: 6 rakaat is the saying of Abu Yusuf, not Abu Hanifa.
It is the practice of many people to pray after the 4 rakat sunnah of jumuah, the zuhr-i ahir prayer (that days zuhr) as a precaution if Jumuah is not valid, and therafter a 2 rakat qaza of missed fajr.
Answer: It is a sunnah to pray Thuhr afterwards if there is a chance that another Jumu^ah prayer in the same city preceded the one oneself participated in. That is, the takbiirah of the Imam preceded. One would only pray Fajr Qadaa if one had missed it. Moreover, praying precautionary Thuhr before the Qadaa of Fajr is invalid in the Hanafi school. One must pray Qadaa first, then the prayer of the time one is in - unless one fears missing it due to lack of time.