workflow rules to update account related products in accont related contacts

workflow rules to update account related products in accont related contacts

Hi,
I have created a custom function in zoho crm , which executes when we create or edit account details , it update account related products in account related contacts,potential.
But there is problem we want that whenever we add products in account related products, it automatically get added in account related contacts and whenever products are deleted from list it get deleted .
so what rules we should implement here to update record by account related products.