my mother expired leaving behind her 2 son and one daughter. there after my sister died leaving behind her husband and one son and one daughter.Wheather the three prson( Son in law, garandson and granddaughter) are leagal demandar of my mothers property ?
your brother in law and his children are well within their rights to demand the share of your deceased sister. they are entitled for 1/3rd share of the property.
Husband and children get there share through there mother and wife . Which means 1/3rd .
Check laws of succession governing the deceased persons and act accordingly.