Dear mr.deepak,
it is true that your company has to be covered as and when your co's strength reached 20 & above inclusive of regular, contract, security even one time employee. Not knowing the act is not an excuse. It is the liability on the part of the principal employer eventhough whether the employee is in service or not. As and when the strength reached 20 u are a coverable unit. The waiver may be claimed if u have 20+ employees presently who have worked earlier and expressing their willings that their share has not been deducted from their monthly salary/wages and it is the decision of the r.c. To decide on this issue.