Your brothers can claim share in your property but for that he has to proved that the property purchased was out of the family money.Give us more information so that we can think in term of sabing your interest.If you purchased said property as a karta of the family then your younger brother has right to claim his share in aforesaid property who is minor at the time of purchase and you leads the family.
The source of fund determines whether the other family members have a right over the property. The fund in your property was from the family money which makes it a joint family property. Hence your brother has a legal right over this property.The title of the property indicate the owner of the land.If the title in the deed and all other documents related to the property has reflected in the name of Brother then he is the absolute owner of the property. He can create / sell /transfer that property as per his wish.
If do so, it never related to the property title.If brother will execute will or other doc. then you husband got share.Your husband should not have funded to the property that never belonged to him anytime. They might have done in the joint family interest whereas if the things are going against him, he cannot legally claim any share in the property.
Reference: Indian succesion act – 202100499-20210042-18387