Registered will and succession certificate or probate

My father , a Hindu, died 6 months ago , leaving all his property to his all 3 daughters through a registered will. My question is can I claim my share of his money from his bank accounts without getting succession certificate as u probably need this if there is no registered will.one sister has filed partition suit against us two sisters and therefore she may not join us in vlaiming the money from bank. According RBI it's not necessary to present a succession certificate .It is also very expensive to get it . What is the cheapest way to get it? Please keep this question and my identity confidential.