Deduction u/s 24 allowed:
The deduction interest u/s 24 is allowable of any kind of loan, however, a certificate from the lender regarding the interest payable/paid and principal amount is required. The said section does not prescribe that loan has to be borrowed from financial institution or bank only for getting the deduction.
Deduction u/s 80C not allowed
However, the deduction u/s 80C for the payment of principal amount of loan borrowed for buying a house or constructing the house has to be from specified institution , company or bank. The said provision is clearly written in section 80C(2)((xviii)