Section 309(a) seems to indicate 6%, but 309(d) says if the loan is more than $10,000, then the loan rate shall be governed by other law. Couldn't locate the 1975 amendment.
Section 309. Installment Loans (Including Revolving Credit Plans)
(a) Maximum rate-An institution may make a charge for an installment loan which complies with the requirements of this section, at a rate not in excess of six dollars ($6) per one hundred dollars ($100) per annum computed on the
original principal amount for the period of the loan. If such loan is one of a series of loans under an agreement ("revolving credit plan") providing a maximum outstanding balance of all such loans at any time, the institution
may make a charge at a rate not in excess of one percent per month on the actual outstanding balance of the loan.
(d) Maximum amount-The original principal amount of any loan, and the total of the principal balances of all loans to one borrower outstanding at any time, for which a charge is made pursuant to the authorization of this section shall not be in excess of ten thousand dollars ($10,000). For any
portion of one or more loans to one borrower in excess of such amount, the charge which the institution may make shall be governed by law other than
this section. ((d) amended July 30, 1975, P.L.108, No.56)