1. You should not worried about the sold property because your father and that sold land are not in your hand now.
2. You can talk about the rented property which was purchased by your father and later it was inherited on your mother's name. actually all legal heirs name should be mentioned on this land. So all legal heirs ahs sharing in this property.
3. Do not worry of NGO people they are also human beings, kindly visit and have a talk with them, If you could not accept their proposal let them go in the court. They can't force you to act beyond the law.
4. For rented property all legal heirs your all siblings will get equal share in the property.
5. No matter the property is in your hand as of now which was purchased by your father. (So as per latest amendment you have to give equal share)
6. If you do not want to give the share then kindly give cash and settle the case by MoU among you all.