The hindu succession act 1956

A person (say 'X'), second son of a widow (say 'Y'), with one living elder married brother (say 'M') (without any issue) and younger sister (say 'N') married (having one adult daughter, one adult son, with her husband living) passes away inestate, survived by one minor Son (say 'Q'), one minor Daughter (say 'R') and his Widow (say 'S'). A property made by the earning of the same deceased person ('X') will be devided amongst: Son (say 'Q'), Daughter (say 'R'), his widow (say 'S') and widow mother of the person (say 'Y') - as all are Class I heir. In case the mother (say 'Y') of the person also passes away, with a 'WILL', those who are authorized, will get the 1/4th share of the property of ('X'). In case, the widow mother ('Y') of the person passes away inestate, fate of the 1/4th share of the person's (say 'X') property will be devided amongst the following, namely: 1. Goes back to the son ('Q'), daughter ('R') and widow ('S') of the inestate person ('X') OR 2. Will be devided into 3 shares, namely: A. one third of widow mother's ('Y') share will go to elder son ('M') & her daughter-in Law (elder brother and his wife of the deceased person ('X')). B.one third of widow mother's ('Y') share will go to younger daughter ("N") & her spouse (younger sister and brother-in Law of the deceased person ('X')) C. one third of the widow mother's ('X') share will go to deceased person' son ('Q'), daughter ('R') and widow ('S') of the deceased inestead person ('X'). Myself is not a lawyer, and above narration is from a friend. Person ('X') is my brother-in Law. Somebody kindly help me whether above clarification is correct or false? If any supportive case law is availble – please apraise me, Sir. Thanks. Ishan Ghosh. Calcutta.