Maternitiy Benfit Act, 1961 provides for many benefits and all covered establishments/employer are under obligation to comply.
e.g; Another 30days Maternity Benefit if pregnant woman employee suffers from sickness due to pregnancy delivery.
The covered establishments/employer canot provide benefits inferior to the provisions of the existing Act but can provide superior benefits, by its own sweet will/wish/decision/policy.
There are private establishment that have already been providing 180days Maternity Benefit to its employees, by their own internal policy.
There are many threads on Maternity Benefit that you and readers may find relevant and useful.
https://www.lawyersclubindia.com/forum/180-days-maternity-leave-for-women-working-in-private-sector-102343.asp
https://www.lawyersclubindia.com/forum/Resignation-after-maternity-leave-79271.asp#.UahsGdKAqWN
https://www.lawyersclubindia.com/forum/Maternity-act-74586.asp#.UXPE3qKAqWM
https://www.lawyersclubindia.com/forum/Forced-to-resign-when-enquired-about-maternity-leaves-75754.asp#.UXPC0qKAqWM
https://www.lawyersclubindia.com/forum/Maternity-leave-salary-76258.asp#.UXPDG6KAqWM
https://www.lawyersclubindia.com/forum/Meternity-leave-75127.asp#.UXPEpaKAqWM
https://www.lawyersclubindia.com/forum/Voluntary-abadonment-from-employment-82097.asp#.Ua8iV9KAqWO
https://www.lawyersclubindia.com/forum/Voluntary-abadonment-from-employment-82097.asp#.U0pY90eBmXX
https://www.lawyersclubindia.com/forum/Regarding-maternity-leave-100692.asp#.U1N830eBmXU