the retrenchment benefit are same for all employees falling under category of workmen, its 15 days wages per years for the completed number of year of services.
As per chapter VB of ID Act in case the number of employee is less than 300 than the notice period shall be one month and if the number of employee in orgnaziation is more than 300 than the same shall be 3 months notice or payment in liue of notice as per Chapter VB of the ID Act/25K & section 25F.
in case of employee on contract, employment termination due to expiry of contract shall not be treated as retrenchment, or due to any condition stipulated therein (see definition).
in case of managers, their services shall be govern by the Agreement of employment, because they are not falling under the category of workmen, and do not have protection under ID Act, which provide provisions of retrenchment.
Further few shop & Establishment also mentioned and has given proceedure for retrenchment, like AP & TN, in case a case, managers shall also be covered.