Wills, probate, letters of administration, powers of attorney
Residue of an estate is whatever is left over after the specific bequests are made.
Is the estate subject to probate? If so, you can obtain a copy of the court documents which will list the details you seek.
Before contesting you will need to see if you have valid grounds to contest the will.
Just being related is not sufficient you need to be able to prove a need. Remember the estate belonged to the deceased and they had the right, subject to certain legal requirements, to give their estate to whomever they like.