you can apply for succession certificate in court in respect of all movable and immovable properties of late father. 

signature of all legal heirs is necessary 

2) ask other legal heirs to give letter in writing that they have no objections of you withdraw the funds lying in deceased father bank account t 

Yes, apply for succession certificate in court. On that basis you can get your share released from Bank. 

If the Bank accepts POA from your siblings in your favour and if your siblings are ready to provide POA in your favour, then you can get your share released from Bank

Or

If your siblings are ready to forego their individual shares in your favour and ready to execute a registered Release/Relinquishment Deed in your favour, then by submitting the Deed , the Bank is likely to release the entire amount to you.  Prior to this, please get clarification from the Bank.

In the circumstances, you need to file a suit at the proper court by engaging a competent lawyer for the purpose, for declaration of your title as a legal heir of the deceased and a direction to the bank for payment of your proportionate share of the deposit proceeds. Make your siblings and the bank concerned as opposite parties in the suit.

If your deceased father had left only this movable asset and no immovable assets then the advise will be to obtain a succession certificate from court of law by placing all your siblings as respondents  and also implead the bank manager as another respondent 

You can also seek dirction against the bank to make payment of your share in the money lying in your deceased father's account

Dear Client,

You can file a petition in probate court to establish your entitlement to a share of the funds. The court can issue orders that require the bank to release your portion of the inheritance. If your siblings are not interested in claiming their shares, you can  negotiate with them to buy out their interests in the inheritance. This would involve reaching a financial agreement where you compensate them for their portion of the funds.

You need to get the succession certificate from court for the same 

- As per law , after the demise of your father intestate, his property and assets would be devolved upon all his legal heirs equally. 

- If there is no nominee in the bank account , then the bank may required legal heir certificate or succession certificate to release the fund of the deceased. 

- If they are not agree , then you can send a legal notice to them for the same , otherwise you will have to apply for legal heir certificate before the Tehsildar.