The restricted holiday is one type of holiday in India and it is similar to the optional holiday.
India is a big country with many festivals that vary from state to state, religion to religion, and community to community. It is almost impossible to have all these festivals or occasions as public holidays.
In general, a company will provide a list of restricted holidays, and employees will select a limited number of holidays in a year. For example, some companies allow employees to have two restricted days besides the gazetted holidays.
Restricted holidays are paid holidays. However, since employees will select different days, the business will run as usual. Please note that restricted holidays are different from gazetted holidays, which are mandatory holidays, declared by the government.