Increament letter with change in terms and conditions in appoinment

Hi, our company is 7 year old, lots of appointment terms changed, can i add new appointment with increment letter or is there any other way to give them new term. I need increament letter format which have change in terms and conditions in appoinment.

Hi,
I suggest you to issue revised terms of appointment as a separate one and not to mingle it with increment letter.
In the revised terms of appointment you need to refer previous appointment letter stating " with further reference to the letter of appointment dated................"

In the case of workers or employees who do not have reportees under them, any change in service condition should be implemented only after giving 21 days notice as per section 9A of the ID Act. However, in the case of those who have reportees under them, you can change the service conditions on mutual agreement.