Succession Certificate

Hi respected Advocates and thank you for taking this up, in your precious time. My father expired on April, 2017 leaving no such big properties or succession. The only small possessions were this Bank Account Balance (in which, my mom is nominee already), a couple of Fixed Deposits attached with the same Bank Account (having nominee in each F.D) and a couple of shares which in total amounts to not more than 25,000. After my father, my family consist of my mother, my 3 married sisters and myself (un-married). Question1: Is a Succession certificate required, in above case (As all the instruments are having Nominee in each)? and can i withdraw this money from bank without any difficulties in Dec, 2018 or not? There are commissions elements which are being deposited in my father's bank account (as he was a Life insurance agent). The commission element was to be transferred to my mother's name and bank. Question 2: There are no objection or any such hindrance from me or my sisters. Is a Succession Certificate required in this matter? Would be great if you can through some light on this matter, as i am a salaried person, having not much income and scared to get mugged by the local Laywer. Thanking you in anticipation. Nitin Singhania. 96749.17689