My sibling went to probate court to change my mother''s will now there is a new document that gives him permission to change things. What are my rights

Without more information, I cannot be sure I am answering this question properly.  But from what you've provided, here's some possibilities: Your mother must still be alive in order for her will to be changed because any will is revocable (meaning it can be changed) until a person dies.  Upon death a will becomes irrevocable and thus unchangeable.  So it sounds as though your sibling is serving as your mom's Power of Attorney (POA) for Property and with her permission he changed her will.  As long as your mother has not been adjudicated as disabled, she has the capacity to make any changes to her will or to allow her appointed POA to make any changes she requests and authorizes.  You don't have any rights unless you have allegations that the will was made under pretenses of fraud, duress or undue influence.....and it will not be contestable until the will becomes effective and that will be upon your mother's death.  Now, if you feel your mother is being exploited in some way, you may consider contacting the Department of Aging in your state to address these concerns.  Hope that helps.