Confirmation Letter in case we made few changes in policy after joining

If employee joined in November & from January we made few changes in policy like made changes in leaves, probation time period .
Then whats the format for confirmation letter in that condition. Please help its urgent

Dear Aarti,
You need to issue the confirmation letter with the conditions applicable on the day. Once the organization came out with new rules / systems in to force then the changes are applicable for the employees who are existing ( even they are working for more than 20yrs also) & are going to be part of the organization till such time they are in force.
Regards
Kameswararao