In a recent finding it was published that there are five (05) major cities across Delhi / NCR which falls under the World's most polluted cities based on annual average PM2.5 concentration (μg/m³). The present study is entirely focused on Delhi / NCR hot-spots in terms of emissions and the measurement is done through the continuous type of air quality monitoring analyzers along with advanced analytical instruments. Various activities like construction, manufacturing, trash burning, production units, burning of organic compounds, power plants, biomass burning, demolition, vehicular emission etc. are the key sources that contribute to poor air quality. As a result of these activities, numerous harmful pollutants with different ionic species (along with gases and aerosols) are released and pose serious threat to both human health and environment. The primary sources of air quality degradation in the present study are identified by methodological & scientific type of measurement done through advanced & sophisticated instruments which are having the capabilities to assess the concentration levels of various pollutants such as PM2.5, PM10, CO, SO2, O3, THC, VOC, NOX, NH3, HONO and HNO3 as well as different ionic species Ca2+, Mg2+, K+, Li2+, Na+, Cl-, NO2-, NO32-, SO42- using standard methods. In the study, four (04) different sites across the Delhi / NCR were chosen as control sites andit was concluded that the largest sources of PM10 emissions are from the industries, road dust and residential as well as biomass burning. The ionic species (unregulated) Ca2+ & Mg2+ were formed to be higher in the samples collected from all the four sites & during the off peak hours the NO32-, SO42- were reported to be in the higher ranges. There is a need of implementation of more stringent & revised guidelines for industries and also to formulate the framework for unorganized sector which are engaged in emissions largely not controlled / reported.