The journalist working with an English daily was allegedly molested in the non-paid area of the metro station on the night of November 13.
A local tea stall help Akhilesh was arrested by the Metro police two days after the incident.
The letter by IWPC president Shobhna Jain and general secretary Aditi Tandon expressed concern over the incident that took "very close" to the Delhi Police headquarters.
The women's right group alleged that there was "delay" on part of the police in responding to the distressed reporter and registering an FIR on her complaint.
The body also highlighted the nature of women journalists' job wherein they have to work till late in the night and commute by public transport.
It added that the police should make the city's women folk feel safe.