Waiving off our rights to a will

Father (Malaysian) passed away and named me and my brother (both are Singaporean) as the beneficiary to his will (there's a house, a car and a bank account). However, as both of us are unable to go back at the same time in order to start the grant of probate, we were wondering if both of us can choose to waive of our rights to the will? With that action, what will happened to my father's will? Will the state passed it to my mother who is Malaysian? We would prefer if if it goes back to our mother. 

Thank you.