What kind of loan they are?? If it is home loan then the debt is created on asset not om individual so the legal heris claiming is has to pay off debt first then claim the ownership of property through inheritance.
Secondly,As per the new nomination rule (2015), the concept of ‘Beneficial Nominee‘ has been introduced. Beneficial nominees are direct dependents of the policy holder i.e., Spouse, children or parents.
As per Insurance Laws (Amendment) Act, 2015 – If an immediate family member such as spouse / parent / child is made as the nominee, then the death benefit will be paid to that person and other legal heirs will not have a claim on the money.
If you (policyholder) nominate your spouse, children or/and parents, they would be Beneficial Nominees. No one else can claim your life insurance policy monies.
Now most probably your brother must have filed nomination in the previous rules where the nominee is just trustee for legal heirs and doesn't own the property so your mother will issue her a legal notice asking her to share the amount equally along with they both jointly have to clear of all the liabilities and then claim your brother asset.