Bank is unable to find nomination detail

Good thing that you have the acknowledgment given by Bank.  Send a letter explaining the position to the Chairman of SBI with a copy of the acknowledgement copy,.

If no reply after 15 days, file a complaint with Banking Ombudsman attached to the Regional Office of RBI near your residence.

Also Nominee should send Registered Legal notice under CP Act, enclosing ACK, and demand for immediate settlment of account, and also enclose prescribed application for claiming the amount, with photo iD/Address proof with copy of ACK, demand for immediate payment of  the outstanding amount with interest within a month, failing which you will be constrained to file complaint in District Consumer Forum for negligence, deficiency of service, claiming compensation of Rs.50,000/- for harassment.  Wait for a month, and then file simple complaint before District Consumer Forum and as proceedings are summary in nature, you can attend the proceeding yourself.  If the amount is not substantial, you can also explore normal procedure at the same time,; by seeking such claims forms prescribed for that purpose by the Bank.

You have posted that:

"I have acknowledgement receipt of nomination in the name of my mother but when i visited to sbi for settlement ,branch manager told me that there is no nomination registered in their record so we have to go through a long legal process."

If you have the receipt then you are not at fault.

Did you record the statement of BM?

Visit again with our witneses and record (audio/visual/minuted/witnessed)?

Thereafter submit a gentle letter (under proper ackowledgment) narrating that on dated.................and dated.............you have visited Mr/Ms....................and he/she ha sstated that......................although you have produced the......................and NO claim papaers have been provided to you, and that you have requested that the internal records of the bank be corrected in ..............say 3 days and releif be provided to you.

If the letter is declined to be recieved, send email/redg. post.

Thereafter you may write to Circle head with a copy to Chairman and CEPD-RBI. 

You may go thru; RBI Master Circular on Customer Services;Section;19 &20..................that is available at website of RBI and should be at website to SBI also.

While submitting claim papers attach copies and show originals and ask the BM to mark on OSV and obtain acknowledgment with seal/date/signature with name , on each paper submitted by you. 

At first thanks to all of you for your suggestion.sir today i wrote an email  to BM alongwith their senior officials and chairmain of SBI and got a quick response from chairman and BM.Copy of response is here: 

महोदय/Dear Sir,

बैंक के अध्यक्ष को संबोधित आपका ई-मेल हमें प्राप्त हुआ और आपकी प्रतिक्रिया के लिए धन्यवाद । हम आपकी शिकायत, शीघ्र समाधान के लिए, मुख्य महाप्रबंधक के निजी सचिव, स्थानीय प्रधान कार्यालय, पटना (pstocgm.lhopat@sbi.co.in) और महाप्रबंधक (ग्राहक सेवा) (gm.customer@sbi.co.in) को अग्रेषित कर रहे हैं ।
We have received your email addressed to the Chairman and thank you for your feedback. We are forwarding your complaint to the P. S. to Chief General Manager, Local Head Office, Patna (pstocgm.lhopat@sbi.co.in) and to the General Manager (Customer Service) (gm.customer@sbi.co.in) for early resolution.
सादर/ Regards,
अध्यक्ष के कार्यकारी सचिव / EXECUTIVE SECRETARY TO CHAIRMAN

The Banks declare the TAT/time for redressal and reply in thier Greivance Redressal Mechanism.

You may submit a gentle communication to ;P. S. to Chief General Manager, General Manager (Customer Service) to reply back to you say in ..................days and supply the resoloution in say..................days.