The cheque number differes upon the sale deed

Hello experts, 1. My client, Ramesh has executed sale deed in favour of Rohit. The consideration is of 1 crores. The Rohit has given 2 cheques of 50 + 50 lakhs. The first cheque having number of 000001 is honoured on the date of sale deed. 2. It is mentioned in the sale deed that Rohit has given 2 cheques dated 1 feb and 1may having number 000001 and 000002 respectively. 3..but in reality ramesh got another cheque having 000001 and 000003. Out of that 000001 is honoured. And 000003 is dishonoured. 4. The remark over the return memo is "alterations require drawers authentication". 5. Now, I want to send demand notice to Rohit. The problem is the cheque we got is not the similar to what is written in the sale deed. But amount date and bank details are same Please guide me, what to do and what is to be mentioned in demand notice. Plus please tell me why it is mentioned on return memo "alteration required drawers authentication" Thankyou in advance