You can avail loan on your investment for any business/personal purpose, but not for speculative ones.
Applicant must have National Savings Certificate / Kisan Vikas Patra in own name. You can not avail loan on someone else savings instrument.
Charges and interest rates on loan keeps varies time to time, Bank may charge processing fees against the loan grant. Different banks have different interest charges against loan.
Amount of loan depends on the bank rules, from where you are going to apply for loan. Normally it depends on the number of years the NSC certificate is.
Loan to be liquidated within the tenure of the instruments or earlier.