Is this a set rule to do F&F after 45 days - can we take legal steps against the company?

I want to know whether any firm registered under shop and establishment act can hold the salary after one resigns the company by serving the requisite notice period. Over here, there is a rule made, that your full & final settlement is done after 45 days. Is this a set rule to do F&F after 45 days. And, can we take legal steps against the company, if after waiting for 45 days, F&F is not done, because there are many cases happened that they don't release salary after 45 days. Not happened with all but in some cases it is now became their practice.

Dear Friend
F&F consists of employee's earnings i.e.PF, Gratuity, Leave wages, Bonus, Last months salary as per applicability and its adjustment against employee's dues towards the company. The dues can be towards an advance, loan, fees towards club and other such amenities etc.
Gratuity shall be paid within 30 days. PF subject to process (transfer/withdrawal) , employer only need to acknowledge wherever required.
Last months' salary shall be paid ideally on the day fixed for salary disbursement, however company can hold it for full an final settlement where they need to take stock from different departments, different agencies about dues from both the sides.
For this purpose company may need some fair and reasonable time. However for F&F settlements in case of resignation there is no clearly prescribed timeline.
In fact it is in interest of the company to settle the full & final at earliest.
In case unjustified and unreasonable delay in payment of Gratuity you can approach Labour commissionerate (authority under Gratuity). If you are drawing less than 24000 you can approach the Labour office for delayed payment of your last month wages also.
Regards
Shailesh Parikh
99 98 97 10 65