Punishment in islam sex before marriage and if the man got married to same women later is it should be compulsory??

It is indeed haram to have sex before you are married.

If the pair is caught, or admits to zina, the worldly punishment is 100 lashes, and they must marry.

If it is not known that zina (adultery) was committed, then only they are responsible, and must repent (tawbah) If the repentance is real and true, Allah is most gracious and forgiving, and be thankful for his grace.

THey must have to maarrryyy ryttt..!

As far as I know, yes. I do know that there are different sects, and some variances of the laws. And there is always debate going on about certain things. I have seen that it is encouraged to marry the one who committed adultery with, but not mandatory. But it IS mandatory to marry another person who also committed adultery. You can't marry someone who has never committed adultery. So if the relationship is repaired, and the repentance is real from both people, marriage is no problem.

Hmmm thanqqq inshallah pray for the couple soon they have to marryyy and repent and also pray for their forgivenesss...