Property of my father in law

Hi sir..I am a muslim from Mumbai and now leaving abroad since 9 yrs with my 2 children seperated from my husband because of his bad behaviours and not looking after me and my kids .my children both are boys of age 20 and 17 now. I didn't took divorce or he given divorce to me since now.in between he got married to another woman 1 yr before and living together.my husband's family is very wealthy family and my father in law have lot of properties in mumbai. I speak to them very rarely and they never given anything to me or my kids for expences and I am working here to meet my and kids expences Now after a long time my father in law called me and saying he want to give one of his property to my kids after his death.he saying he going to make documents accordingly. So my question is will there will come any right to my husband on that property if father in law giving as a gift to my kids? My husband have another wife and brothers and sisters too.they will have any right on that gifted property to my kids? Wat will be the exact and smooth procedure to receive that property from father in law to my kids. I don't want anything from them.I need my kids rights.I didn't married yet again.