Or ur c6 can ask whether it's possible to wave his right as an owner. He can give his share to his mom outright and thus his Mother will be the legal owner of the property 100%. Te only problem is ur mortgage. Might ask for some legal advice? Wish I could be more helpful in this. But i wnt be surprised that they wnt pay back the mortgage. Good luck with ethg
Transfer of title may require bank's consent as the creditor, the title deed is in the possession of the mortgage bank. The mortgage loan has to be reassessed in context of the repayment ability of your brother in law and 99. Perhaps, they are working hard on this.