In section 24 is telling only Interest portion allowed
but Income tax definitions under section 2(28A)under Income tax act, Interest definition has been given as follows:
“interest” means interest payable in any manner in respect of any moneys borrowed or debt incurred (including a deposit, claim or other similar right or obligation) and includes any service fee or other charge in respect of the moneys borrowed or debt incurred or in respect of any credit facility which has not been utilised
so according to this we can claim processing fees also