Regarding the Sunnah of the Jumu`ah Prayer, there are slight differences among scholars regarding them. We see that people inBangladesh are probably following the Hanafi school of thought that says it is recommended to pray four rak`ahs before Jumu`ah and four after. It is legitimate for a Muslim layman to follow the madhhab of the people of his country as long as he does not know for sure that their opinion in a certain matter is incorrect. So, don’t be confused over this issue.
The Hanafi school of thought says that it is Sunnah to pray four rak`ahs before Jumu`ah prayer. See: al-Ikhtyar by al-Mawsili and Hashiyat ibn `Abideen. They quote the following narration in support of their opinion: Ibn Mas`oud (may Allah be pleased with him) used to pray four rak`ahs before Jumu`ah (Al-Tirmidhi).
In addition to Hanafis, imam Sufyan al-Thawri and imam `Abdullah ibn al-Mubarak used to adopt the opinion of Ibn Mas`oud (may Allah be pleased with him), that is to pray four recommended rak`ahs before Jumu`ah. See: al-Jami` al-Kabir by al-Tirmidhi.
In regards to praying Sunnah after Jumu`ah Prayer, the Hanafi school of thought say that it is recommended to pray four rak`ahs after Jumu`ah prayer. They base their opinion on the Hadith in which the Prophet (peace and blessings be upon him) said: “If you pray after Jumu`ah, let it be four rak`ahs; but if you in a hurry, pray two rak`ahs in the mosque and two at home.” (Muslim) See: al-Ikhtyar by al-Mawsili and Hashiyat ibn `Abideen.