To an ITES i.e "Information technology enabled services" , companies are exempted from the certain provisions of Labour laws like Bombay shop and establishment act. For eg. provisions relating to working hours, change of time, shift working etc. But there is no total exemption of applicability of a particular law.
As regard notice period, I am of the view that the notice is not governed by any labour law, but it is governed by the contract of employment between the company and employee or the sevices conditions as applicable to the particular category of the emplyee. One can have different notice period for different category of the employee.
I hope your query is clarified.
As explained by Mr Kapoor, the notice period is a matter covered by contract of employment. Normally, for higher positions, a longer notice period is provided, to take care of the vacuum that may result, by making alternate arrangement.
Labour laws are applicable to those employees coming under the category of "Workmen" as stipulated in various labour laws. These are devised to safegaurd the interest of employees and the exploitiation of them.
As far as the notice period of any other staff, Managers and others are considered, the terms and conditions mentioned in Appointment letter hold good for any dispute. These employees can not appeal in the labour court, but they can file a case in civil court and the court may ask the both parties to abide the terms and conditions mutully agreed upon.
The notice period may vary for different positions.