How to enter in tally

In 2013-2014

Supplier A/c Dr. 72000

To Discount Received 72000

In 2014-2015

Bank A/c Dr. 72000

To Supplier A/c 72000

Discount received is an income item. so it must be credited in the previous year. Debit the supplier for debit note. Cheque received comes under real accounts. Follow real account rules, that is Debit the bank account and credit the giver (supplier a/c). Mr.Priyul shah suggestion is correct.

DEbit has to be raised from us, If the supplier has a debot note means he made charges to you. Please check whether he is given debit note or credit note.