Suggest On Applicability Of PF,ESI & Gratuity

Dear All,
Please read the following and suggest-
There are 5 no.s of companies in a group. There is 1 father company to all and 4 other companies are the subsidiaries/sister concern of the father company. Now the father company is registered under PF,ESI and Gratuity as it exceeds required no. of manpower. The other companies which are sister concerns are yet not registered for PF,ESI,Gratuity as the manpower's to each co. is less than 10. What I understand that from PF point view other 4 companies should be registered as they all are sister concern and the father company is registered under PF. I would like to know whether the same principle is applicable for ESI and Gratuity also? Please guide.
Rgds..
DG

It is same in the case of ESI and Gratuity also that departments or branches will be taken together for coverage. However, if all the units have separate Financial statements and do file IT returns separately, it becomes independent units and due to that reason the other units may not come under the purview of ESI or Gratuity Act provided they do not employ 10 employees.
Regards,
Madhu.T.K