I would like to tell you that EPF is applicable to salary up to 6500 or less (means Basic+DA per month) at the time of their joining, and it is applicable to organizations having 10 or more employees now, not 20.
In case both the above terms are not complied with, then voluntarily an organization can avail of this facility. They can be part of the EPF by requesting with the EPF organization.
Once an employee is registered under the EPF organization, then he/she has to deduct PF from their salary even if the salary is above 6500/month (for example; an employee joined the organization with a salary of 5000 per month and is liable to deduct PF amount from their salary. After two years, their salary has been revised to 10,000 per month. However, as a principle, PF is not applicable because they crossed the 6500/month limit, but there is a law limit to restrict this act. They still remain a part of PF, and PF has to be deducted from their salary until they are working in the same organization).