Me n my husband are separated since last 5months after lot of issues I had gone through mental and p

Me n my husband are separated since last 5months after lot of issues I had gone through mental and physical torture now I want to know wat are the rights of a wife in husband's properties n kids rights according to law and we r muslims.my in laws n husband are ready to divorce me they planned to give me 1 property from my husband's 6 properties including our own flat wer we use to reside but now my husband is pretending that he sold our flat to one of his brother.and kids were with me till now but my husband started avoiding my kids he din met my kids from last 40days so I sent my kids to my in laws were we came to know that my husband got married to another women n he s hiding it from us.ow everything is open up I want to know my kids n my Right towards his properties n wats his responsibility toward us. My in law said we asked our lawyer and he suggested that Muslim man can marry 4 women if he s capable to take responsibility is it true? Pls suggest as I am going to meet them tomor