Late Evening Working for Female Employees in Govt. Undertakings eg NTPC, BSNL etc.

Hi, My wife is working in one of the major Govt. India undertakings as an Executive. She used to observe shift duties but no shift duty beyond 6:00 PM as of now given to female employees. Now she has been told that she will be now required to work till 8:30 - 09:00 PM shift too. Here I would also like to inform you that in that case she will be required to work alone till late evenings i.e. up to around 09:00 PM in entire department/floor. . She works in a large multistory building and having only one security guard at entry point in main gate. Further, there is no transport facility is being provided to employees. My questions are: 1. based on above mentioned circumstances, can any organisation ask to perform late evening duties to female employees? 2. by maximum what time any female employees are supposed to work in late evenings under above mentioned circumstances? 3. if female employees are supposed to work in late evenings, what all facilities/security measures supposed to be provided by the organisation? Regards,