Can second wife also get a share of pension after husbands death

Sir, My father a state govt employee worked as junior assistant in d.e.o office I am the son of second wife first wife gave her consent to the second marriage and past 30 years we were living with out any clashes in a same home all together.first wife has a son.my father passed away in November 2014.now first wife asks compassionate appointment to her son and says that to take full pension and benifits.we all are mentioned as the legalheirs including our married sister.but in office they are saying that second wife doesn't get full pension.sir is there any chance of getting pension to second wife as any one has no objection to it?at present we didn't get any benifits or pension as the matter not settled.please help us we don't have clarity wether second wife gets full pension or not.