1. Sir, there is no relevance of minimum wages as far as the ESI Act, 1948, and the rules/regulations framed thereunder are concerned. Both employees' share as well as employers' share are to be deducted even if the minimum wages of an employee are less than as laid down under the relevant laws of the appropriate government. If any employer/unit is paying less than minimum wages, it is for the appropriate authorities to examine the issue under the minimum wages laws applicable in that state where said unit is located.
2. The only exemption is that in respect of employees getting average daily wages "up to and inclusive of rupees one hundred" are exempted from 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.