The operators which botched to meet the call drop yardsticks for 2G and 3G services include Aircel, state-run BSNL and Tata Teleservices.
The rate of call drops in certain locations worsened in the July-September quarter.
The data showed that the incidences of call drops for 2G services slightly worsened.
Meanwhile, for 3G services it increased from a figure of no location to 3.23 per cent of the total locations surveyed.
The overall call drop rate for 2G services, marginally increased to 1.64 per cent from 1.63 per cent in the preceding three-month period.
According to the regulator uidelines, the call drop rate should not be more than 2 per cent and for worst affected mobile phones it should not be more than 3 per cent.
The telecom operators in the country are in continuous pressure from the government to improve the quality of services, with the regulator having mandated carriers to compensate users for call drops from January2016.