1) succession certificate is for movable properties .
2) for immovable properties you would need letters of administration of estate of deceased if he had died intestate .
3)deed of family settlement/ partition can be entered into among the family members . it has to be duly stamped and registered
4) mother can make a will in respect of her 1/4th share in the properties . or if she so desires execute gift deed / relinquishment deed
5) for gift deed/ relinquishment deed stamp duty is nominal if made in favour of family member in Maharashtra
6) contact a local lawyer . as far as main house is concerned other legal heirs should vacate the house when family settlement is arrived at to avoid future legal complications