My wife works with a renowned private school. She was paid only 3 months salary during her maternity leave and when asked the HR asked her to look at the private secondary school code.
We are considering challenging the schools position based on Sec 27 of the Maternity Benefits Act which should override any contradictory law/contract that specifies benefits that are less favourable to the woman than those awarded by the Maternity Benefits Act.
Definitely any code which is against the minimum prescribed welfare policy has to be condemned at any point of time. But please note that it is available with only the High Courts or Supreme Courts to declare any law as unconstitutional or invalid and not any inferior Court.