1. Sir, there is no relevance of minimum wages so far as ESI Act, 1948 and rules/regulations framed thereunder is concerned. Both employees' share as well as employers' share are to be deducted even if the minimum wages of an employee is less than as laid down under relevant laws of appropriate government. If any employer/unit is paying less than minimum wages, it is for the appropriate authorities to examine the issue under minimum wages laws applicable in that state where said unit is located.
2. Only exemption is that in respect of employees getting average daily wages "upto and inclusive of rupees one hundred" are exempted for paying their employees contribution. Please see Rule 52 of ESI (Central) Rules, 1950. However, in such cases also the employers' share of contribution is required to be paid.