If I borrow a loan from friends and relatives for acquiring or constructing a house, can I claim a deduction for the interest paid on such loan?

Yes, you can claim the deduction of interest paid on a loan taken from friends and relatives, as the source of the loan is irrelevant for claiming the deduction of Housing Loan interest; thus, you are allowed to deduct the interest paid on the loan you took out from friends and family. However, the borrowed money must be used for the purchase, building, reconstruction, repairs, or renewal of the residential property. 

Further, you would also need to obtain a certificate from your friend(s) to support your claim for interest deduction. Please note that, to claim deduction of the principal amount under Section 80C, a loan must be taken from a Bank / financial institution.