His father died and he left for them one flat and this flat was rent by person and this person died also the sister of this person took the flat and refused to hand it over to them. They put a case in the court then on of the owners brother refused to deal with the court and he said this is "Shirk Billah " because the country is not rolled by Shariah but by Taghoot so we shouldn't deal with court in country controlled by the French low is this correct or not.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. Basically a Muslim has to avoid going to civil courts; he must not go to such courts for any reason. Allah Says (interpretation of meaning): {Have you not seen those (hyprocrites) who claim that they believe in that which has been sent down to you, and that which was sent down before you, and they wish to go for judgement (in their disputes) to the Tâghût (false judges) while they have been ordered to reject them. But Shaitân (Satan) wishes to lead them far astray. And when it is said to them: "Come to what Allâh has sent down and to the Messenger (Muhammad SAW)," you (Muhammad SAW) see the hypocrites turn away from you (Muhammad SAW) with aversion. }[4:60-61]. However, if a Muslim cannot get his right except by presenting his case to a civil court then it is permissible for him to go there because the necessities permit to overpass the prohibitions. Allah Says (interpretation of meaning) in this concern: {…while He has explained to you in detail what is forbidden to you, except under compulsion of necessity?… }[6:119]. If there is no Islamic court or authority that could help one then he may seek help from such courts. Therefore, this brother may take his case to a civil court since there is no other way to get his right. If one of the brothers do not want to take his right or gives up his right then the other brothers may sue the oppressor to take their rights. Allah knows best.