Yes. Schools can change the referral payment amount at any point of time by starting a new referral program.
This does not however, change existing invoices raised for payments for successful referrals based on previous referral amount. For instance, if on the 1st of March the school changes a referral benefit from Rs. 3000 per admission to Rs. 2000 per admission, it does not impact invoices raised before that date for payment to be made by the school.