Sir,
EPF Act Applicability
The EPF Act applies to all establishments employing 20 or more persons. Please note that this count includes security staff, temporary staff, assistants, etc. If all employees are earning more than Rs. 6500, there is currently no need for coverage. However, you will have to start contributing when any employee is hired at a salary below Rs. 6500.
Administrative Charges
Regarding the payment of minimum administrative charges, I believe that if there are no employees for whom you are contributing, there is no need to pay administrative charges. You can inform the relevant PF office of the actual situation and also mention that you will apply for a code number once you hire any employees who are statutorily eligible to contribute to PF.
Regards,
Pradheep