In case the documents are not in English you would need to provide translated copies attested by the Indian Embassy
All banks and financial institutions insist on a local General Power of Attorney holder for NRI /PIO /OCI applicants. The GPOA holder could be any blood relative as in father, mother, brother, sister in case no one is available even a friend could be a sked to hold the Power of Attorney
Most important the GPOA has to be in the format of the bank where you are applying. Each bank has a specific format.
This GPOA has to be notarised / Registered in India, if the applicant is in India. Incase the applicant is overseas the GPOA has to be notarised by the Indian Embassy