Who are all claim mother's property

hello My brother in law had a trouble with his sibilings.they are 3 of his parents.one of them are women also. Now they discuss about their property.Elder brother told that the property(1200 sq.ft land with house)was in mother name only. so she settle with little money with my BIL. After his marriage he was staying separetly with his wife's side relatives.BILs mother staying with his elder sons and daughter house alternative month. last two years back BIL's father was dead. All the property in Mother's name only. Question: 1. MY BIL have any rights in his mother,s named document like fathers property. 2. All the three children have equal rights? 3. Elder brother told that the mother give some(?, not equal/little)amount to my BIl.according her own wish? Is this correct point? 4.These property earned by his fater's income and registered with his wife. she is a housewife only..In that grandsons have any rights to file a case? Please clear my doubt....thank u