Giving NOC without relinquishing my share

This is with reference to my ex deceased husband’s father’s house in Mumbai. My ex husband died in 1995 and I remarried in 2007 and now settled in USA. My ex father in law was the owner of the house and he died few years ago. The said house is a Co-op Housing Society and has only BMC employees living in this society. As told to me any sale or transfer of this house should be to a BMC employee. The house deed has mine and my ex husband’s and my ex 3 sister in law’s name on it. Recently my ex sis in law asked me to give her a NOC to transfer the house deed to my ex mother in law’s name, after which they can sell the house. She also told me that I won’t get any share as I am remarried. 1) What is the law in India for a widow who remarries and is still a nominee in the property owned by her ex deceased father in law? 2) After the property is transferred to mother in law’s name will she have the right to remove mine and ex deceased husband’s name from the deed? I also need to know If I am legally eligible for a share from the sale of the house as my name still exists on the house deed as a nominee. They have a customer who works for BMC and wants to buy this house. Should I give the NOC? If yes, What should I write on the NOC without keeping up my right on the property. Please guide.